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.rs
\v | 5i'
.LP
\fBMONTAGE: FIN DE LA RECOMMANDATION Q.707 EN\(hyT\* | TE DE CETTE PAGE\fR 
.sp 2P
.LP
\v'9P'
\fBRecommendation\ Q.708\fR 
.RT
.sp 2P
.sp 1P
.ce 1000
\fBNUMBERING\ OF\ INTERNATIONAL\ SIGNALLING\ POINT\ CODES\fR 
.EF '%	Fascicle\ VI.7\ \(em\ Rec.\ Q.708''
.OF '''Fascicle\ VI.7\ \(em\ Rec.\ Q.708	%'
.ce 0
.sp 1P
.LP
\fB1\fR 	\fBIntroduction\fR 
.sp 1P
.RT
.PP
This Recommendation describes the numbering scheme of
international signalling point codes for Signalling System\ No.\ 7 networks.
The technical aspects of the signalling networks are specified in
Recommendation\ Q.705.
.PP
The worldwide signalling network is structured into two functionally independent 
levels, namely the international and national levels. This 
structure makes possible a clear division of responsibility for signalling
network management and allows numbering plans of signalling points of the
international network and the different national networks to be independent 
of one another. 
.PP
It is also noted that the point code is intended to be processed
within the Message Transfer Part of each signalling point or signalling
transfer point, so that there is no direct relationship to the telephone, 
data, or ISDN numbering. 
.RT
.sp 2P
.LP
\fB2\fR 	\fBNumbering of International Signalling Points\fR 
.sp 1P
.RT
.PP
2.1
A 14\(hybit binary code is used for the identification of
signalling points.
.sp 9p
.RT
.PP
2.2
An international signalling point code (ISPC) should be
assigned to each signalling point which belongs to the international signalling 
network. For some network environment, one physical network node may serve 
as more than one signalling point, and may therefore be assigned more than 
one 
signalling point code.
.sp 9p
.RT
.PP
2.3
All international signalling point codes (ISPC) should
consist of three identification sub\(hyfields as indicated in Figure\ 1/Q.708. 
The sub\(hyfield of 3\ bits (NML) should identify a world geographical 
zone. The 
sub\(hyfield of 8\ bits (K\(hyD) should identify a geographical area or 
network in a specific zone. The sub\(hyfield of 3\ bits (CBA) should identify 
a signalling point in a specific geographical area or network. The combination 
of the first and 
second sub\(hyfields could be regarded as a signalling area/network code
(SANC).
.sp 9p
.RT
.PP
2.4
Each country (or geographical area) should be assigned at least
one signalling area/network code (SANC).
.sp 9p
.RT
.PP
2.5
Two of the zone identifications, namely\ 0 and\ 1 codes, are
reserved for future allocation.
.sp 9p
.RT
.PP
2.6
The system of international signalling point codes (ISPC) will
provide for 6\ \(mu\ 256\ \(mu\ 8 (12288) ISPCs.
.sp 9p
.RT
.PP
2.7
If a country (or geographical area) should require more than\ 8
international signalling points, one or more additional signalling area/network 
code(s) (SANC) would be assigned to it. 
.bp
.sp 9p
.RT
.PP
2.8
Lists of signalling area/network codes (SANC) to be used in the
development of international signalling point codes (ISPC) is given in 
Annex\ A to this Recommendation. It shows SANCs assigned to each geographical 
area that already has other code assignments in existing public telecommunication 
networks. All codes not shown on the lists are spare codes.
.sp 9p
.RT
.PP
2.9
The assignment of signalling area/network codes (SANC) is to be
administered by the CCITT. The assignment of signalling point identifications 
in the sub\(hyfield (CBA) will be made by each country (or geographical 
area) and the CCITT Secretariat notified. 
.sp 9p
.RT
.PP
2.10
The Member countries of the International Telecommunications Union not 
mentioned in Annex\ A who wish to take part in the international signalling 
network or those Members that require an additional signalling area/network 
code (SANC) should ask the Director of the CCITT for the assignment of an
available SANC. In their request, they may indicate the available SANC
preferred.
.sp 9p
.RT
.PP
2.11
The Director of the CCITT takes care that:
.sp 9p
.RT
.LP
	\(em
	generally the assignments are made on a one by one basis and
contiguously for a given geographical area, or a given signalling network.
(Geographical designations, or network names, may be entered in the
list.)
.LP
	\(em
	the needs of each Member country of the International
Telecommunication Union for a new SANC shall be met under all circumstances.
Should there not be any additional contiguous codes available, a new sequence 
of contiguous codes shall be opened up for the country concerned. Such 
a new 
code sequence will be established firstly at the bottom of the block of 
spare codes at the end of the lists in Annex\ A, and secondly at the bottom 
of 
existing sequences when it is likely that the adjacent code groups will not
require the spares.
.LP
	\(em
	code assignments appearing in Annex\ A, but obviously not
required anymore because the networks concerned are reached with other SANCs
will be deleted from the Annex.
.PP
2.12
Assignments by the Director of the CCITT of SANC as well as
assignments by countries of the signalling point identifications will be
published in the Operational Bulletin of the ITU. The representation of ISPC
should be shown in decimal form in each sub\(hyfield, i.e.\ Z\(hyUUU\(hyV 
where Z, UUU, and\ V are corresponding to bits NML, K\(hyD and CBA, respectively. 
.sp 9p
.RT
.LP
.rs
.sp 20P
.ad r
\fBFigure 1/Q.708, (M), p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.ce 1000
ANNEX\ A
.ce 0
.ce 1000
(to Recommendation Q.708)
.sp 9p
.RT
.ce 0
.ce 1000
\fBLists of \fR \fBSignalling Area/Network Codes\fR \fB(SANC)\fR 
.sp 1P
.RT
.ce 0
.PP
\fINote\fR \ \(em\ These lists are shown by the decimal representation, 
i.e.\ Z\(hyUUU where\ Z is zone identification and UUU is area/network 
identification.
.sp 1P
.RT
.sp 1P
.ce 1000
\fBZone 2\fR 
.sp 1P
.RT
.ce 0
.sp 1P
.sp 2P
.LP
	\fICode\fR 	\fIGeographical Area or Signalling Network\fR 	
	2\(hy004
	Greece
.sp 1P
.RT
.LP
	2\(hy008
	Netherlands (Kingdom of the)
.LP
	2\(hy012
	Belgium
.LP
	2\(hy016 through 2\(hy023
	France
.LP
	2\(hy024
	Monaco
.LP
	2\(hy028
	Spain
.LP
	2\(hy032
	Hungarian People's Republic
.LP
	2\(hy036
	German Democratic Republic
.LP
	2\(hy040
	Yugoslavia (Socialist Federal Republic of)
.LP
	2\(hy044 through 2\(hy046
	Italy
.LP
	2\(hy052
	Romania (Socialist Republic of)
.LP
	2\(hy056
	Switzerland (Confederation of)
.LP
	2\(hy060
	Czechoslovak Socialist Republic
.LP
	2\(hy064
	Austria
.LP
	2\(hy068
	United Kingdom of Great Britain and Northern Ireland (British
Telecom)
.LP
	2\(hy072
	United Kingdom of Great Britain and Northern Ireland (Mercury
Telecommunications Limited)
.LP
	2\(hy076
	Denmark
.LP
	2\(hy080 and 2\(hy081
	Sweden
.LP
	2\(hy084
	Norway
.LP
	2\(hy088
	Finland
.LP
	2\(hy100
	Union of Soviet Socialist Republics
.LP
	2\(hy120
	Poland (People's Republic of)
.LP
	2\(hy124 through 2\(hy131
	Germany (Federal Republic of)
.LP
	2\(hy132
	Gibraltar
.LP
	2\(hy136
	Portugal
.LP
	2\(hy140
	Luxembourg
.LP
	2\(hy144
	Ireland
.LP
	2\(hy148
	Iceland
.LP
	2\(hy152
	Albania (Socialist People's Republic of)
.LP
	2\(hy156
	Malta (Republic of)
.LP
	2\(hy160
	Cyprus (Republic of)
.LP
	2\(hy168
	Bulgaria (People's Republic of)
.LP
	2\(hy172
	Turkey
.LP
Zone 2, Spare Codes: 224
.LP
.PS 10
.sp 1P
.ce 1000
\fBZone 3\fR 
.sp 1P
.RT
.ce 0
.sp 1P
.sp 2P
.LP
	\fICode\fR 	\fIGeographical Area or Signalling Network\fR 	
	3\(hy004
	Canada
.sp 1P
.RT
.LP
	3\(hy016
	St. Pierre and Miquelon (French Department of)
.LP
	3\(hy020 through 3\(hy059
	United States of America
.LP
	3\(hy060
	Puerto Rico
.LP
	3\(hy064
	Virgin Islands (USA)
.bp
.sp 1P
.ce 1000
\fBZone 3\fR \fI(cont.)\fR 
.sp 1P
.RT
.ce 0
.sp 1P
.sp 2P
.LP
	 \fICode\fR \fIGeographical Area or Signalling Network\fR 3\(hy068, 3\(hy069 
and 3\(hy070 
	Mexico
.sp 1P
.RT
.LP
	3\(hy076
	Jamaica
.LP
	3\(hy080
	French Antilles
.LP
	3\(hy084
	Barbados
.LP
	3\(hy088
	Antigua and Barbuda
.LP
	3\(hy092
	Cayman Islands
.LP
	3\(hy096
	British Virgin Islands
.LP
	3\(hy100
	Bermuda
.LP
	3\(hy104
	Grenada
.LP
	3\(hy108
	Montserrat
.LP
	3\(hy112
	St. Kitts and Nevis
.LP
	3\(hy116
	St. Lucia
.LP
	3\(hy120
	St. Vincent and the Grenadines
.LP
	3\(hy124
	Netherlands Antilles
.LP
	3\(hy128
	Bahamas (Commonwealth of the)
.LP
	3\(hy132
	Dominica (Commonwealth of)
.LP
	3\(hy136
	Cuba
.LP
	3\(hy140
	Dominican Republic
.LP
	3\(hy144
	Haiti (Republic of)
.LP
	3\(hy148
	Trinidad and Tobago
.LP
	3\(hy152
	Turks and Caicos Islands
.LP
	3\(hy156
	Guadeloupe
.LP
	3\(hy160
	Martinique
.LP
Zone 3, Spare Codes: 228
\v'1P'
.LP
.PS 10
.sp 1P
.ce 1000
\fBZone 4\fR 
.sp 1P
.RT
.ce 0
.sp 1P
.sp 2P
.LP
	\fICode\fR 	\fIGeographical Area or Signalling Network\fR 	
	4\(hy008
	India (Republic of)
.sp 1P
.RT
.LP
	4\(hy020
	Pakistan (Islamic Republic of)
.LP
	4\(hy024
	Afghanistan (Democratic Republic of)
.LP
	4\(hy026
	Sri Lanka (Democratic Socialist Republic of)
.LP
	4\(hy028
	Burma (Socialist Republic of the Union of)
.LP
	4\(hy030
	Lebanon
.LP
	4\(hy032
	Jordan (Hashemite Kingdom of)
.LP
	4\(hy034
	Syrian Arab Republic
.LP
	4\(hy036
	Iraq (Republic of)
.LP
	4\(hy038
	Kuwait (State of)
.LP
	4\(hy040
	Saudi Arabia (Kingdom of)
.LP
	4\(hy042
	Yemen (Arab Republic)
.LP
	4\(hy044
	Oman (Sultanate of)
.LP
	4\(hy046
	Yemen (People's Democratic Republic of)
.LP
	4\(hy048
	United Arab Emirates
.LP
	4\(hy050
	Israel (State of)
.LP
	4\(hy052
	Bahrain (State of)
.LP
	4\(hy054
	Qatar (State of)
.LP
	4\(hy056
	Mongolian People's Republic
.LP
	4\(hy058
	Nepal
.LP
	4\(hy060
	United Arab Emirates (Abu Dhabi)
.LP
	4\(hy062
	United Arab Emirates (Dubai)
.LP
	4\(hy064
	Iran (Islamic Republic of)
.bp
.sp 1P
.ce 1000
\fBZone 4\fR \fI(suite)\fR 
.sp 1P
.RT
.ce 0
.sp 1P
.sp 2P
.LP
	\fICode\fR 	\fIGeographical Area or Signalling Network\fR 	
	4\(hy080
	Japan
.sp 1P
.RT
.LP
	4\(hy100
	Korea (Republic of)
.LP
	4\(hy104
	Viet Nam (Socialist Republic of)
.LP
	4\(hy108
	Hong Kong
.LP
	4\(hy110
	Macao
.LP
	4\(hy112
	Democratic Kampuchea
.LP
	4\(hy114
	Lao People's Democratic Republic
.LP
	4\(hy120
	China (People's Republic of)
.LP
	4\(hy135
	Korea (Democratic People's Republic of)
.LP
	4\(hy140
	Bangladesh (People's Republic of)
.LP
	4\(hy144
	Maldives (Republic of)
.LP
.sp 1
Zone 4, Spare Codes: 223
.LP
.PS 10
.sp 5
.sp 1P
.ce 1000
\fBZone 5\fR 
.sp 1P
.RT
.ce 0
.sp 1P
.sp 2P
.LP
	\fICode\fR 	\fIGeographical Area or Signalling Network\fR 	
	5\(hy004
	Malaysia
.sp 1P
.RT
.LP
	5\(hy010
	Australia
.LP
	5\(hy020
	Indonesia (Republic of)
.LP
	5\(hy030
	Philippines (Republic of)
.LP
	5\(hy040
	Thailand
.LP
	5\(hy050
	Singapore (Republic of)
.LP
	5\(hy056
	Brunei Darussalam
.LP
	5\(hy060
	New Zealand
.LP
	5\(hy070
	Guam
.LP
	5\(hy072
	Nauru (Republic of)
.LP
	5\(hy074
	Papua New Guinea
.LP
	5\(hy078
	Tonga (Kingdom of)
.LP
	5\(hy080
	Solomon Islands
.LP
	5\(hy082
	Vanatu (Republic of)
.LP
	5\(hy084
	Fiji (Republic of)
.LP
	5\(hy086
	Wallis and Futuna Islands
.LP
	5\(hy088
	American Samoa
.LP
	5\(hy090
	Niue Island
.LP
	5\(hy092
	New Caledonia and Dependencies
.LP
	5\(hy094
	French Polynesia
.LP
	5\(hy096
	Cook Islands
.LP
	5\(hy098
	Western Samoa (Independent State of)
.LP
	5\(hy100
	Kiribati (Republic of)
.LP
	5\(hy102
	Tuvalu
.LP
.sp 1
Zone 5, Spare Codes: 232
.LP
.PS 10
.bp
.sp 1P
.ce 1000
\fBZone 6\fR 
.sp 1P
.RT
.ce 0
.sp 1P
.sp 2P
.LP
	\fICode\fR 	\fIGeographical Area or Signalling Network\fR 	
	6\(hy004
	Egypt (Arab Republic of)
.sp 1P
.RT
.LP
	6\(hy006
	Algeria (Algerian Democratic and Popular Republic)
.LP
	6\(hy008
	Morocco (Kingdom of)
.LP
	6\(hy010
	Tunisia
.LP
	6\(hy012
	Libya (Socialist People's Libyan Arab Jamahiriya)
.LP
	6\(hy014
	Gambia (Republic of the)
.LP
	6\(hy016
	Senegal (Republic of the)
.LP
	6\(hy018
	Mauritania (Islamic Republic of)
.LP
	6\(hy020
	Mali (Republic of)
.LP
	6\(hy022
	Guinea (Republic of)
.LP
	6\(hy024
	C\* | te d'Ivoire (Republic of the)
.LP
	6\(hy026
	Burkina Faso
.LP
	6\(hy028
	Niger (Republic of the)
.LP
	6\(hy030
	Togolese Republic
.LP
	6\(hy032
	Benin (People's Republic of)
.LP
	6\(hy034
	Mauritius
.LP
	6\(hy036
	Liberia (Republic of)
.LP
	6\(hy038
	Sierra Leone
.LP
	6\(hy040
	Ghana
.LP
	6\(hy042
	Nigeria (Federal Republic of)
.LP
	6\(hy044
	Chad (Republic of)
.LP
	6\(hy046
	Central African Republic
.LP
	6\(hy048
	Cameroon (Republic of)
.LP
	6\(hy050
	Cape Verde (Republic of)
.LP
	6\(hy052
	Sao Tome and Principe (Democratic Republic of)
.LP
	6\(hy054
	Equatorial Guinea (Republic of)
.LP
	6\(hy056
	Gabon Republic
.LP
	6\(hy058
	Congo (People's Republic of the)
.LP
	6\(hy060
	Zaire (Republic of)
.LP
	6\(hy062
	Angola (People's Republic of)
.LP
	6\(hy064
	Guinea\(hyBissau (Republic of)
.LP
	6\(hy066
	Seychelles (Republic of the)
.LP
	6\(hy068
	Sudan (Republic of the)
.LP
	6\(hy070
	Rwanda (Republic of)
.LP
	6\(hy072
	Ethiopia (People's Democratic Republic of)
.LP
	6\(hy074
	Somali Democratic Republic
.LP
	6\(hy076
	Republic of Djibouti
.LP
	6\(hy078
	Kenya (Republic of)
.LP
	6\(hy080
	Tanzania (United Republic of)
.LP
	6\(hy082
	Uganda (Republic of)
.LP
	6\(hy084
	Burundi (Republic of)
.LP
	6\(hy086
	Mozambique (People's Republic of)
.LP
	6\(hy090
	Zambia (Republic of)
.LP
	6\(hy092
	Madagascar (Democratic Republic of)
.LP
	6\(hy094
	Reunion (French Department of)
.LP
	6\(hy096
	Zimbabwe (Republic of)
.LP
	6\(hy098
	Namibia
.LP
	6\(hy100
	Malawi
.LP
	6\(hy102
	Lesotho (Kingdom of)
.LP
	6\(hy104
	Botswana (Republic of)
.LP
	6\(hy106
	Swaziland (Kingdom of)
.LP
	6\(hy108
	Comoros (Islamic Federal Republic of the)
.LP
	6\(hy110
	South Africa (Republic of)
.LP
.sp 3
Zone 6, Spare Codes: 203
.bp
.sp 1P
.ce 1000
.PS 10
\fBZone 7\fR 
.sp 1P
.RT
.ce 0
.sp 1P
.sp 2P
.LP
	\fICode\fR 	\fIGeographical Area or Signalling Network\fR 	
	7\(hy004
	Belize
.sp 1P
.RT
.LP
	7\(hy008
	Guatemala (Republic of)
.LP
	7\(hy012
	El Salvador (Republic of)
.LP
	7\(hy016
	Honduras (Republic of)
.LP
	7\(hy020
	Nicaragua
.LP
	7\(hy024
	Costa Rica
.LP
	7\(hy028
	Panama (Republic of)
.LP
	7\(hy032
	Peru
.LP
	7\(hy044
	Argentine Republic
.LP
	7\(hy048
	Brazil (Federative Republic of)
.LP
	7\(hy060
	Chile
.LP
	7\(hy064
	Colombia (Republic of)
.LP
	7\(hy068
	Venezuela (Republic of)
.LP
	7\(hy072
	Bolivia (Republic of)
.LP
	7\(hy076
	Guyana
.LP
	7\(hy080
	Ecuador
.LP
	7\(hy084
	Guiana (French Department of)
.LP
	7\(hy088
	Paraguay (Republic of)
.LP
	7\(hy092
	Suriname (Republic of)
.LP
	7\(hy096
	Uruguay (Eastern Republic of)
.LP
Zone 7, Spare Codes: 236
\v'1P'
.LP
.PS 10
.sp 2P
.LP
\fBRecommendation\ Q.709\fR 
.RT
.sp 2P
.sp 1P
.ce 1000
\fBHYPOTHETICAL\ SIGNALLING\ REFERENCE\ CONNECTION\fR 
.EF '%	Fascicle\ VI.7\ \(em\ Rec.\ Q.709''
.OF '''Fascicle\ VI.7\ \(em\ Rec.\ Q.709	%'
.ce 0
.sp 1P
.LP
\fB1\fR 	\fBIntroduction\fR 
.sp 1P
.RT
.PP
This Recommendation specifies how the elements of a signalling
connection are combined to meet the signalling requirements of the networks
that it supports. Included are parameters for signalling transfer delay 
in both national and international networks, and overall signalling delay 
that such 
combinations will produce, together with the availability required, to 
enable the performance of the network served by the signalling network 
to be 
maintained.
.PP
A probabilistic approach is been taken, i.e.,\ limits are specified
for mean and\ 95% of connections. These figures will apply to the normal
operation of a signalling network. No consideration is given to the \*Qunusually 
long\*U signalling paths that are found in some signalling networks. Any 
unusual routing caused by some network structures and/or reconfigurations 
due to 
network failure are considered to be covered in the remaining\ 5% of
connections.
.PP
The hypothetical signalling reference connection (HSRC) for
international working is specified in this Recommendation by defining
the constituent parts of:
.RT
.LP
	i)
	the international section,
.LP
	ii)
	the national section.
.PP
In any combination of those sections to produce an overall
hypothetical signalling reference connection, it is necessary to consider 
what impact each of the component parts (international and two national 
sections) 
have on each other and the full hypothetical signalling reference connection. 
This means that certain national or international limits such as the maximum 
number of signalling transfer points allowed in a signalling relation (see
Recommendation\ Q.705, \(sc\ 5.2) require modification and account of this 
has been taken in this Recommendation. 
.bp
.sp 2P
.LP
\fB2\fR 	\fBRequirements of networks served by the signalling connection\fR 
.sp 1P
.RT
.PP
To meet the requirements of services carried on the network served by the 
signalling network, the signalling connection performance should be 
closely aligned with those requirements. Since these services are ultimately 
to be carried on an ISDN, the hypothetical signalling reference connection 
is 
based upon the hypothetical reference connection produced for that network
(Recommendation\ G.801).
.PP
However, for a considerable time the majority of services in the
network served by the signalling network will be telephony\(hybased and account
must therefore be taken of the reference connection for conventional telephony 
application (Recommendation\ G.101). 
.RT
.sp 2P
.LP
\fB3\fR \fBHypothetical signalling reference connection components for\fR 
\fBlink\(hyby\(hylink signalling\fR 
.sp 1P
.RT
.sp 1P
.LP
\fB
3.1
	\fIGeneral\fR 
.sp 9p
.RT
.PP
The components of an hypothetical signalling reference connection are signalling 
points and STPs which are connected in series by signalling data links 
to produce a signalling connection (Note\ 1). The number of signalling 
points and STPs depend on the size of the network. Two limits are prescribed 
to cover mean or\ 95% cases. Separate cases are allowed for large countries 
and 
average sized countries (Note\ 2). This section outlines the considerations
involved in formulating a hypothetical signalling reference connection for
link\(hyby\(hylink signalling and details the number of hypothetical signalling
reference connection components and the delays they produce.
.PP
\fINote\ 1\fR \ \(em\ The term signalling point is used to designate use 
of the user function in a signalling point: whether or not STP function 
is presented irrelevant in this context. The term STP is used to designate 
use of the STP 
function in a signalling point: whether or not user function is present is
irrelevant in this context.
.PP
\fINote\ 2\fR \ \(em\ When the maximum distance between an international
switching centre and a subscriber who can be reached from it does not exceed
1000\ km or, exceptionally, 1500\ km, and when the country has less than
\fIn\fR \ \(mu\ 10\u7\d subscribers, the country is considered as of average 
size. A 
country with a larger distance between an international switching centre 
and a subscriber, or with more than \fIn\fR \ \(mu\ 10\u7\d subscribers, 
is considered as of 
large size. (The value of\ \fIn\fR is for further study.)
.RT
.sp 1P
.LP
3.1.1
	\fINumber of signalling points in the hypothetical signalling\fR 
\fIreference connection\fR 
.sp 9p
.RT
.PP
The number of signalling points in the hypothetical signalling
reference connection has been determined by considering the maximum number 
of links allowed by the Telephone Routing Plan (Q.13/E.171). These Recommendations 
define \*Qlast choice\*U backbone routes and only a small proportion of 
traffic 
take these routes. Traffic generated in metropolitan areas, generally the
largest source of traffic, usually takes far fewer links to an international
switching centre. Even for rural areas a connection to the international
switching centre will not generally be required to follow the backbone
route.
.PP
Limitation of the number of signalling points required will reduce the 
signalling delay, considering that signalling point delay, forms the largest 
component of signalling delay.
.RT
.sp 1P
.LP
3.1.2
	\fINumber of STPs in an hypothetical signalling reference\fR 
\fIconnection\fR 
.sp 9p
.RT
.PP
The number of STPs in the hypothetical signalling reference
connection is a function of the number of signalling points, and the signalling 
network topology used to connect these signalling points. The number of 
STPs 
should be kept to a minimum in order to limit the signalling delay. In some
signalling relationship, associated signalling may be used for which no STPs
are required. In others, one or more STPs may be used. For international
signalling relationship, it is recommended that no more than\ 2 STPs be 
used in a signalling relation. (See Recommendation\ Q.705, \(sc\ 5.2.) 
.RT
.sp 1P
.LP
3.1.3
	\fISignalling network availability\fR 
.sp 9p
.RT
.PP
The availability of a signalling connection is an important network parameter. 
It is necessary for the availability to be significantly better than the 
availability of the component being controlled (e.g.\ a circuit). A figure 
of 10\ minutes down time per year maximum unavailability is recommended 
for any particular signalling route set (Recommendation\ Q.706, \(sc\ 1.1). 
.PP
This corresponds to an availability of 0.99998, which can be achieved by 
the use of suitable network redundancies. 
.bp
.RT
.sp 1P
.LP
3.1.4
	\fISignalling message transfer delay\fR 
.sp 9p
.RT
.PP
Signalling message transfer delay is another important network
parameter. It affects call set up delay and also affects network response 
time to service requests made during a call. In this Recommendation, the 
transmission propagation delays are not included
(see \(sc\ 7.2).
.RT
.sp 1P
.LP
3.2
	\fIInternational component of hypothetical signalling reference\fR 
\fIconnection\fR 
.sp 9p
.RT
.PP
The international component of the hypothetical signalling
reference connection includes all international signalling points in the
connection and the STPs carrying signalling messages between the signalling
points. The maximum number of signalling points and STPs allowed are listed 
in Table\ 1/Q.709. 
.PP
The unavailability of the overall international component of the
signalling network should not exceed the following totals per year for 
both the 50 and 95\ percent cases. 
.RT
.LP
	\(em
	20 minutes for large country to large country,
.LP
	\(em
	30 minutes for large country to average\(hysized country, and
.LP
	\(em
	40 minutes per year for average\(hysized country to
average\(hysized country.
.LP
.sp 2
.ce
\fBH.T. [T1.709]\fR 
.ce
TABLE\ 1/Q.709
.ce
\fBMaximum number of signalling points and STPs in\fR 
.ce
\fBinternational component\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(72p) | cw(42p) | cw(42p) | cw(42p) .
Country size  (Note)	Percent of  connections	Number  of STPs	Number of  signalling points
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	mean	3	
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			3
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	95	4	
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	mean	4	
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			4
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	95	5	
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	mean	5	
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			5
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	95	
7
.TE
.LP

\fINote\fR
\ \(em\ See Note 2 to \(sc 3.1.
.nr PS 9
.RT
.ad r
\fBTableau 1/Q.709 [T1.709], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 3
.PP
The maximum signalling transfer delay under normal conditions for the international 
component of a connection should not be worse than the values listed in 
Table\ 2/Q.709. 
.sp 1P
.LP
3.3
	\fINational components of hypothetical signalling reference\fR 
\fIconnection\fR 
.sp 9p
.RT
.PP
The national components of the hypothetical signalling reference
connection includes all national exchanges in the connection (but does not
include the international switching centre in the country) and all STPs
carrying signalling messages between the national exchanges and between the
highest level national exchange and the international switching centre. The
maximum number of signalling points and STPs allowed are listed in
Table\ 3/Q.709.
.bp
.RT
.ce
\fBH.T. [T2.709]\fR 
.ce
TABLE\ 2/Q.709
.ce
\fBMaximum signalling delays for international component\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(72p) | cw(42p) | cw(42p) sw(42p) , ^  | ^  | c s 
^  | ^  | c | c.
Country size	Percent of  connections	Delay (Note) (ms)
		Message type	Simple  (e.g. answer)	 {
Processing intensive
(e.g. IAM)
 }
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	mean	390	\ 600
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	95	410	\ 620
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	mean	520	\ 800
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	95	540	\ 820
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	mean	650	1000
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	95	690	
1040
.TE
.LP

\fINote\fR
\ \(em\ Only the mean delay component from Table 4/Q.706, Table 3/Q.725 and
Table\ 1/Q.766 have been used in calculating the delay. Further study is
required, e.g. for the mean values as well as the inclusion of overload and/or 95\ percentile cases of each component value.
.nr PS 9
.RT
.ad r
\fBTableau 2/Q.709 [T2.709], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 2
.ce
\fBH.T. [T3.709]\fR 
.ce
TABLE\ 3/Q.709
.ce
\fBMaximum number of signalling points and STPs in\fR 
.ce
\fBnational components\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(72p) | cw(42p) | cw(30p) | cw(42p) .
Country size  (Note 1)	Percent of  connections	Number  of STPs	Number of  signalling points
_
.T&
cw(72p) | cw(42p) | cw(30p) | cw(42p) .
	mean	3	3
.T&
lw(72p) | cw(42p) | cw(30p) | cw(42p) .
Large			
.T&
lw(72p) | cw(42p) | cw(30p) | cw(42p) .
	95	4	4
_
.T&
lw(72p) | cw(42p) | cw(30p) | cw(42p) .
	mean	2	2
.T&
lw(72p) | cw(42p) | cw(30p) | cw(42p) .
Average\(hysized			
.T&
lw(72p) | cw(42p) | cw(30p) | cw(42p) .
	95	3	3
.TE
.LP

\fINote\ 1\fR
\ \(em\ See Note 2 to \(sc 3.1.
.LP
\fINote\ 2\fR
\ \(em\ The values in this Table are provisional. (A higher number of
signalling points and/or STPs might be included in a national network,
e.g.\ in the case that a two\(hylevel hierarchical signalling network is adopted. This matter is for further study.)
.nr PS 9
.RT
.ad r
\fBTableau 3/Q.709 [T3.709], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.PP
The unavailability of each of the overall national components of the signalling 
network should not exceed the following totals per 
year:
.LP
	\(em
	20 minutes for mean case of average\(hysized countries,
.LP
	\(em
	30 minutes for 95 percent case of average\(hysized countries
and mean case of large countries, and
.LP
	\(em
	40 minutes for 95 percent case of large
countries.
.PP
\fINote 1\fR \ \(em\ Although the signalling component of the international 
switching centre in the country was not included in Table\ 3/Q.709, it 
is 
included in the unavailability objectives.
.PP
\fINote 2\fR \ \(em\ The hypothetical signalling reference connection define 
a unique path through the national and international networks, therefore 
when 
considering the overall unavailability of each national component, no account 
is taken of any standby path, if provided, in that national network. The 
values given are based on those for each component route\(hyset as specified
in Recommendation\ Q.706, \(sc\ 1.1. They are provisional and for further
study.
.PP
The maximum signalling transfer delay under normal conditions for each 
of the national components of a connection should not be worse than the 
values listed in Table\ 4/Q.709. 
.RT
.LP
.sp 1
.ce
\fBH.T. [T4.709]\fR 
.ce
TABLE\ 4/Q.709
.ce
\fBMaximum signalling delays for each national component\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(72p) | cw(42p) | cw(42p) sw(42p) , ^  | ^  | c s 
^  | ^  | c | c.
Country size	Percent of  connections	Delay (Notes 1 and 2) (ms)
		Message type	Simple  (e.g. answer)	 {
Processing intensive
(e.g. IAM)
 }
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
	mean	390	600
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
	95	520	800
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
	mean	260	400
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
	95	390	600
.TE
.LP

\fINote\ 1\fR
\ \(em\ See Note to Table 2/Q.709.
.LP
\fINote\ 2\fR
\ \(em\ The delay does not include any delay for the International Switching Centre in the country, which is included in the international component.
.nr PS 9
.RT
.ad r
\fBTableau 4/Q.709 [T4.709], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 2
.sp 2P
.LP
\fB4\fR 	\fBOverall signalling delay for link\(hyby\(hylink signalling\fR 
.sp 1P
.RT
.PP
From the hypothetical signalling reference connection and the
values of message transfer times given for signalling point and STP, the
overall signalling delay due to signalling point, and STP delays can be
determined from Tables\ 2 and\ 4 of this Recommendation, for a given load in a
given network. Average delays and 95\ percentile delays are given in
Table\ 5/Q.709 for various combinations of large and average\(hysized countries. 
Average signalling point and STP delays at normal loading are assumed.
.bp
.PP
These values must be increased by the transmission propagation
delays (see Table 1/Q.41).
.RT
.ce
\fBH.T. [T5.709]\fR 
.ce
TABLE\ 5/Q.709
.ce
\fBMaximum overall signalling delays\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(72p) | cw(42p) | cw(42p) sw(42p) , ^  | ^  | c s 
^  | ^  | c | c.
Country size	Percent of  connections	Delay (Note) (ms)
		Message type	Simple  (e.g. answer)	 {
Processing intensive
(e.g. IAM)
 }
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	mean	1170	1800
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	95	1450	2220
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	mean	1170	1800
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	95	1450	2220
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average	mean	1170	1800
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	95	1470	2240
.TE
.LP

\fINote\fR
\ \(em\ See Note to Table 2/Q.709.
.nr PS 9
.RT
.ad r
\fBTableau 5/Q.709 [T5.709], p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 2P
.LP
\fB5\fR \fBHypothetical signalling reference connection (HSRC) components\fR 
\fBfor end\(hyto\(hyend signalling\fR 
.sp 1P
.RT
.sp 1P
.LP
5.1
	\fIGeneral\fR 
.sp 9p
.RT
.PP
The components of a hypothetical signalling reference connection
are signalling end points (SEP), signalling points with SCCP relay function
(SPR) and STPs which are connected in series by signalling data links to
produce an end\(hyto\(hyend signalling connection (Note\ 1). The number 
of the various signalling nodes depends on the size of the network. Two 
limits are prescribed to cover mean or 95%\ cases. Separate cases are allowed 
for large countries and average\(hysized countries (Note\ 2). This section 
outlines the considerations 
involved in formulating a hypothetical signalling reference connection and
details the number of hypothetical signalling reference connection components 
and the delays they produce. 
.RT
.LP
	\fINote\ 1\fR \ \(em
	a)
	 Signalling End Point (SEP) \(em This includes processing in UP/AP (User 
part/application part), 
SCCP (Signalling connection control part),
MTP (Message transfer part) and also MTP\(hySCCP\(hyUP/AP
.LP
	b)
	Signalling Point with SCCP relay function (SPR) \(em
This includes only processing in MTP\(hySCCP\(hyMTP
.LP
	c)
	Signalling Transfer Point \(em This includes processing in MTP exclusively.
.PP
\fINote\ 2\fR \ \(em\ When the maximum distance between an international
switching centre and a subscriber who can be reached from it does not exceed
1000\ km or, exceptionally, 1500\ km, and when the country has less than
\fIn\fR \ \(mu\ 10\u7\d subscribers, the country is considered as of average 
size. A 
country with a larger distance between an international switching centre 
and a subscriber, or with more than \fIn\fR \ \(mu\ 10\u7\d subscribers 
is considered as of 
large size. (The value of \fIn\fR is for further study.)
.bp
.sp 1P
.LP
5.1.1
	\fINumber of signalling nodes in the end\(hyto\(hyend HSRC\fR 
.sp 9p
.RT
.PP
The same signalling network is used for end\(hyto\(hyend messages and
link\(hyby\(hylink messages. This means that the maximum number of signalling 
nodes is equal in both cases. The maximum number of signalling nodes from 
the 
originating node to the destination node is 18 in 50\ percent of the connections 
and 23 in 95\ percent of the connections except for average\(hysized to 
average\(hysized country. In that case the value is\ 24.
.PP
In general a fast transfer of end\(hyto\(hyend signalling messages has 
to be required. For such messages a route with a minimum number of signalling 
transfer and relay points is highly desirable.
.PP
It is desirable to use the message routing of the MTP (STP functions) as 
far as possible and trying in this way to avoid processing in higher layers 
(SCCP or user functions). 
.RT
.sp 1P
.LP
5.1.2
	\fISignalling network availability\fR 
.sp 9p
.RT
.PP
The availability of a signalling connection is an important network parameter. 
It is necessary for the availability to be significantly better than the 
availability of the component being controlled (e.g.\ a circuit). A figure 
of ten minutes down time per year maximum unavailability is recommended 
for any particular signalling route set (Recommendation\ Q.706, \(sc\ 1.1). 
.PP
This corresponds to an availability of 0.99998, which can be achieved by 
the use of suitable network redundancies. 
.RT
.sp 1P
.LP
5.1.3
	\fISignalling message transfer delay\fR 
.sp 9p
.RT
.PP
Signalling message transfer delay is another important network
parameter. It affects call set up delay and also affects network response 
time to service requests made during a call. 
.PP
The use of signalling points with SCCP relay functions (SPR) should be 
kept to a minimum. In an SPR additional processing is performed which causes 
an additional delay, for example address translation for\ CR or\ UDT message 
types (processing intensive messages) or a local reference message mapping 
for CC or DT messages (processing simple message types). The cross office 
transit time 
for SPR is defined in Q.716. The cross\(hyoffice transit time for an SEP 
is equal to \fIT\fR\d\fIc\fR\\d\fIu\fR\uin Q.766 or\ Q.725 and for an STP 
is equal to \fIT\fR\d\fIc\fR\\d\fIs\fR\u 
in\ Q.706.
.RT
.sp 1P
.LP
5.2
	\fIInternational component of hypothetical signalling reference\fR 
\fIconnection\fR 
.sp 9p
.RT
.PP
The international component of the hypothetical signalling
reference connection includes all international signalling nodes (e.g.\ SPR
and\ STP) in the connection. The maximum number of SPRs and STPs allowed are
listed in Table\ 6/Q.709.
.RT
.ce
\fBH.T. [T6.709]\fR 
.ce
TABLE\ 6/Q.709
.ce
\fBMaximum number of SPRs and STPs in international component\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(72p) | cw(42p) | cw(42p) | cw(42p) .
Country size	Percent of  connections	Number  of STPs	Number of SPRs
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	mean	4	2
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	95	4	3
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	mean	6	2
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	95	6	3
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	mean	8	2
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	95	8	4
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau 6/Q.709 [T6.709], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.PP
The unavailability of the overall international component of the signalling 
network should not exceed the following totals per year for both the 50\ 
and 95\ percent cases: 
.LP
	\(em
	20 minutes for large country to large country;
.LP
	\(em
	30 minutes for large country to average\(hysized country, and
.LP
	\(em
	40 minutes per year for average\(hysized country to
average\(hysized country.
.PP
The maximum delay at the signalling nodes under normal conditions for the 
international component of a connection should not be worse than the 
values listed in Table\ 7/Q.709.
.LP
.sp 2
.ce
\fBH.T. [T7.709]\fR 
.ce
TABLE\ 7/Q.709
.ce
\fBMaximum delay at the signalling nodes for international component\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(72p) | cw(42p) | cw(42p) sw(42p) , ^  | ^  | c s 
^  | ^  | c | c.
Country size	Percent of  connections	Delay (ms)
		Message type	Processing simple	Processing intensive
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	mean	300	440
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	95	410	620
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	mean	340	480
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	95	450	660
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	mean	380	520
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	95	600	880
.TE
.LP

\fINote\ 1\fR
\ \(em\ The maximum signalling nodes delay is the sum of all cross\(hyoffice
delays involved.
.LP
\fINote\ 2\fR
\ \(em\ All values are provisional.
.nr PS 9
.RT
.ad r
\fBTableau 7/Q.709 [T7.709], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 3
.sp 1P
.LP
5.3
	 \fINational components of hypothetical signalling\fR \fIreference connections\fR 
.sp 9p
.RT
.PP
The national components of the hypothetical signalling reference
connection includes all national signalling nodes (e.g.,\ SEP, SPR, STP) 
in the connection (but does not include the international switching centre 
in the 
country). The maximum number of SEPs, SPRs and STPs allowed are listed in
Table\ 8/Q.709.
.RT
.PP
The unavailability of each of the overall national components of the signalling 
network should not exceed the following totals per year: 
.LP
	\(em
	20 minutes for mean case of average\(hysized
countries;
.LP
	\(em
	30 minutes for 95 percent case of average\(hysized countries
and mean case of large countries, and
.LP
	\(em
	40 minutes for 95 percent case of large
countries.
.bp
.ce
\fBH.T. [T8.709]\fR 
.ce
TABLE\ 8/Q.709
.ce
\fBMaximum number of SEPs, SPRs and STPs\fR 
.ce
\fBin national component\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(48p) | cw(48p) | cw(36p) | cw(36p) | cw(36p) .
Country size	Percent of  connections	Number of  STPs	Number of  SPRs	Number of  SEPs
_
.T&
cw(48p) | cw(48p) | cw(36p) | cw(36p) | cw(36p) .
.	mean	4	1	1
.T&
cw(48p) | cw(48p) | cw(36p) | cw(36p) | cw(36p) .
Large				
.T&
cw(48p) | cw(48p) | cw(36p) | cw(36p) | cw(36p) .
.	95	5	2	1
_
.T&
cw(48p) | cw(48p) | cw(36p) | cw(36p) | cw(36p) .
.	mean	2	1	1
.T&
cw(48p) | cw(48p) | cw(36p) | cw(36p) | cw(36p) .
Average\(hysized				
.T&
cw(48p) | cw(48p) | cw(36p) | cw(36p) | cw(36p) .
.	95	4	1	1
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau 8/Q.709 [T8.709], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 1
.PP
\fINote\ 1\fR \ \(em\ Although the signalling component of the international 
switching centre in the country is not included in Table\ 8/Q.709, it is 
included in the unavailability objectives.
.PP
\fINote\ 2\fR \ \(em\ The hypothetical signalling reference connection 
defines a unique path through the national and international networks, 
therefore when 
considering the overall unavailability of each national component, no account 
is taken of any standby path, if provided, in that national network. The 
values given are based on those for each component route\(hyset as specified 
in 
Recommendation\ Q.706, \(sc\ 1.1.
.RT
.PP
The maximum delay at the signalling nodes under normal conditions for each 
of the national components of a connection should not be worse than 
the values listed in Table\ 9/Q.709.
.LP
.sp 1
.ce
\fBH.T. [T9.709]\fR 
.ce
TABLE\ 9/Q.709
.ce
\fBMaximum delay at the signalling nodes for each national
.ce
component\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(72p) | cw(42p) | cw(42p) sw(42p) , ^  | ^  | c s 
^  | ^  | c | c.
Country size	Percent of  connections	Delay (ms)
		Message type	Processing simple	Processing intensive
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
	mean	300	440
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
	95	430	\ 640
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
	mean	260	400
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
	95	300	4
.TE
.LP40
\fINote\ 1\ \(em\ \fR
The maximum signalling nodes delay is the sum of all cross\(hyoffice
delays involved.
.LP
\fINote\ 2\ \(em\ \fR
All values are provisional.
.nr PS 9
.RT
.ad r
\fBTableau 9/Q.709 [T9.709], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.sp 2P
.LP
\fB6\fR 	\fBOverall signalling delay for end\(hyto\(hyend signalling\fR 
.sp 1P
.RT
.PP
The link\(hyby\(hylink signalling delay is applicable where messages are 
processed by each signalling point (e.g.\ during call establishment). The 
use of end\(hyto\(hyend signalling intended to reduce the overall signalling 
delay. 
.PP
From the hypothetical signalling reference connection and the values of 
message transfer times given for SEPs, SPRs and STPs, the overall signalling 
delay due to the node delays can be determined from Tables\ 7 and\ 9 of 
this 
Recommendation, for a given load in a given network. Average delays and
95\ percentile delays are given in Table\ 10/Q.709 for various combinations of
large and average\(hysized countries. Average signalling node delays at normal
loading are assumed.
.RT
.LP
.sp 1
.ce
\fBH.T. [T10.709]\fR 
.ce
TABLE\ 10/Q.709
.ce
\fBMaximum overall delay at the signalling nodes\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(72p) | cw(42p) | cw(42p) sw(42p) , ^  | ^  | c s 
^  | ^  | c | c.
Country size	Percent of  connections	Delay (ms)
		Message type	Processing simple	Processing intensive
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	mean	\ 900	1320
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	95	1270	1900
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Large	mean	\ 900	1320
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	95	1180	1740
_
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	mean	900	1320
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
to			
.T&
lw(72p) | cw(42p) | cw(42p) | cw(42p) .
Average\(hysized	95	1200	1760
.TE
.LP
\fINote\ 1\ \(em\ \fR
The maximum signalling nodes delay is the sum of all cross\(hyoffice
delays involved.
.LP
\fINote\ 2\ \(em\ \fR
All values are provisional.
.nr PS 9
.RT
.ad r
\fBTableau 10/Q.709 [T10.709], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 2
.sp 2P
.LP
\fB7\fR 	\fBRemarks\fR 
.sp 1P
.RT
.PP
7.1
The above values for signalling delays assumes a message length
distribution as given in Table\ 2/Q.706 and Table\ 2/Q.725, with a mean 
message length of 15\ octets. However, a message length of e.g.\ 128\ octets 
for SCCP user data in CR and CC messages and 255\ octets for SCCP user 
data in DT messages are permissible. For such a message length the transmission 
time at 64\ kbit/s is, in each signalling node, about 15\ ms (128\ octets) 
to 30\ ms (255\ octets) 
longer.
.sp 9p
.RT
.PP
7.2
When defining an overall signalling delay the propagation delay
must be included. This delay cannot be completely neglected due to the
geographical size of the HSRC (see Table\ 1/Q.41).
.bp
.sp 9p
.RT
.LP
\fBMONTAGE: PAGE 368 = BLANCHE\fR 
.sp 1P
.RT
.LP
.bp
.sp 1P
.ce 1000
\v'3P'
SECTION\ 3
.ce 0
.sp 1P
.ce 1000
\fBSIMPLIFIED\ MESSAGE\ TRANSFER\ PART\fR 
.ce 0
.sp 1P
.sp 2P
.LP
\fBRecommendation\ Q.710\fR 
.RT
.sp 2P
.sp 1P
.ce 1000
\fBSIMPLIFIED\ MTP\ VERSION\ FOR\ SMALL\ SYSTEMS\fR 
.EF '%	Fascicle\ VI.7\ \(em\ Rec.\ Q.710''
.OF '''Fascicle\ VI.7\ \(em\ Rec.\ Q.710	%'
.ce 0
.sp 1P
.LP
\fB1\fR 	\fBField of application\fR 
.sp 1P
.RT
.PP
1.1
This Recommendation is applicable for systems using a
simplified MTP version to interface to the public network(s).
.sp 9p
.RT
.PP
1.2
The MTP functions specified in \(sc 3 of this Recommendation may be applied 
in general for small systems, e.g., PABX's, remote concentrators,\ etc., 
interfacing with the message transfer part described in Recommendations\ 
Q.702, Q.703, Q.704 and\ Q.707. 
.sp 9p
.RT
.PP
1.3
The Recommendation applies only for digital access arrangements.
.sp 9p
.RT
.PP
1.3.1
In case one channel carries signalling information for more than one multiplex 
system, at least one additional channel should be pre\(hyassigned as a 
stand\(hyby signalling link in a multiplex system other than that which 
contains the active channel. This allows the changeover and changeback 
procedures 
specified in \(sc\(sc\ 3.4.4 and\ 3.4.5 to be performed.
.PP
1.3.2
The stand\(hyby channel(s) should not be used as B\(hychannel(s).
.PP
1.4
Only the associated mode of signalling is applicable.
.sp 9p
.RT
.PP
1.5
A variety of information types may be supported by the signalling system, 
e.g., relating to circuit switched call control and packet 
communication.
.sp 9p
.RT
.sp 2P
.LP
\fB2\fR 	\fBFunctional content\fR 
.sp 1P
.RT
.PP
The functional requirements are as follows:
.RT
.PP
2.1
The network call control functions are as specified in
Recommendation\ Q.930\ (I.451).
.sp 9p
.RT
.PP
\fINote\fR \ \(em\ Different network layer protocols (circuit switching 
and packet switching) may be supported by using the protocol discriminator 
included in Recommendation\ Q.930. As an alternative, different network 
layer entities 
may access the interface functions directly. In that case, the interface
functions will use separate service indicator codes to discriminate the
applicable network layer entity. This will be similar to the use of SAPI
specified in Recommendation\ Q.920. Which principle to be applied is determined 
by the Administration/RPOA. 
.bp
.PP
2.2
The minimum set of Message Transfer Part functions are
specified in Recommendations\ Q.702, Q.703, Q.704 and\ Q.707, with the
qualifications specified in \(sc\ 3 of this Recommendation.
.sp 9p
.RT
.PP
2.3
The additional interface functions required for the proper
operation of the D\(hychannel call control functions in combination with the
message transfer part functions, are specified in \(sc\ 4 of this Recommendation 
(see Figure\ 1/Q.710).
.sp 9p
.RT
.LP
.rs
.sp 16P
.ad r
\fBFigure 1/Q.710, (MC), p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 2P
.LP
\fB3\fR 	\fBMessage Transfer Part (MTP) functions\fR 
.sp 1P
.RT
.sp 1P
.LP
3.1
	\fIGeneral\fR 
.sp 9p
.RT
.PP
The MTP functions as specified in Recommendations Q.702, Q.703,
Q.704 and\ Q.707 are applicable. However, the following exceptions and
modifications to those Recommendations may be applied for the PABX system, 
see \(sc\(sc\ 3.2\(hy3.4. 
.PP
In order to prevent fraudulent use of the signalling network, it has to 
be ensured that no signalling messages generated by a PABX can be routed 
further than the public exchange to which the PABX has access. The manner in
which this is made may be dependent on national circumstances and system
implementations. An example of how such a function could be implemented is
given in \(sc\ 3.5.
.RT
.sp 1P
.LP
3.2
	\fILevel 1\fR  | (Recommendation Q.702)
.sp 9p
.RT
.PP
Only digital signalling data links are relevant.
Recommendation\ Q.702, \(sc\ 6, is not applicable.
.RT
.sp 2P
.LP
3.3
	\fILevel 2\fR  | (Recommendation Q.703)
.sp 1P
.RT
.sp 1P
.LP
3.3.1
	\fIInitial alignment procedure\fR  | (Recommendation Q.703, \(sc 7)
.sp 9p
.RT
.PP
In the initial alignment procedure specified in
Recommendation\ Q.703, \(sc\ 7, only the emergency proving is applicable. 
Thus, in states \*Qaligned\*U and \*Qproving\*U of the initial alignment 
procedure status 
indication\ \*QN\*U is not sent.
.RT
.sp 1P
.LP
3.3.2
	\fIProcessor outage\fR  | (Recommendation Q.703, \(sc 8)
.sp 9p
.RT
.PP
The processor outage function specified in Recommendation\ Q.703,
\(sc\ 8, is not applicable.
.PP
When the level 2 function receives an indication that a processor
outage situation exists at the remote and (through the reception of status
signal units indicating processor outage), it transmits status signal units
indicating \*Qout of service\*U.
.bp
.RT
.sp 1P
.LP
3.3.3
	\fIFlow control\fR  | (Recommendation Q.703, \(sc 9)
.sp 9p
.RT
.PP
The sending of the link status indication \*QB\*U from the PABX is not 
applicable. 
.PP
When the level 2 function of the PABX receives the link status
indication\ \*QB\*U, no action is taken by the PABX.
.RT
.sp 2P
.LP
3.4
	\fILevel 3\fR  | (Recommendation Q.704)
.sp 1P
.RT
.sp 1P
.LP
3.4.1
	\fIRouting label\fR  | (Recommendation Q.704, \(sc 2.2)
.sp 9p
.RT
.PP
The signalling link selection (SLS) field defined in \(sc\ 2.2.4 is
always coded\ 0000.
.RT
.sp 1P
.LP
3.4.2
	\fIMessage routing function\fR  | (Recommendation Q.704, \(sc 2.3)
.sp 9p
.RT
.PP
The load sharing function between link sets and within a link set defined 
in \(sc\ 2.3.2 is not applicable. 
.RT
.sp 1P
.LP
3.4.3
	\fIMessage discrimination\fR  | (Recommendation Q.704, \(sc 2.4)
.sp 9p
.RT
.PP
The discrimination function defined in \(sc 2.4.1 is not
applicable.
.RT
.sp 1P
.LP
3.4.4
	\fIChangeover\fR  | (Recommendation Q.704, \(sc 5)
.sp 9p
.RT
.PP
Changeover between link sets is not applicable.
.PP
Initiation of changeover at the reception of a changeover order from the 
remote end of a link is not applicable (c.f. Recommendation\ Q.704, 
\(sc\ 3.2.2).
.PP
The buffer updating procedure defined in \(sc 5.4 is not
applicable.
.PP
At reception of a changeover order (or emergency changeover order) an emergency 
changeover acknowledgement is sent in response. 
.PP
The message retrieval procedure defined in \(sc 5.5 is not applicable.
.PP
Diversion of traffic is performed at expiry of a time\(hyout T1 (c.f.
Recommendation\ Q.704, \(sc\ 16.8) is started when the changeover is
initiated.
.RT
.sp 1P
.LP
3.4.5
	\fIChangeback\fR  | Recommendation Q.704, \(sc\ 6)
.sp 9p
.RT
.PP
Changeback between link sets is not applicable.
.PP
The sequence control procedure defined in \(sc\ 6.3 is not applicable. 
At reception of a changeback declaration, a changeback acknowledgement 
is sent in response. 
.PP
For the purpose of ensuring message sequence integrity, the time
controlled diversion procedure specified in \(sc\ 6.4 is used.
.RT
.sp 1P
.LP
3.4.6
	\fIForced rerouting\fR  | Recommendation Q.704, \(sc\ 7)
.sp 9p
.RT
.PP
Forced rerouting is not applicable.
.RT
.sp 1P
.LP
3.4.7
	\fIControlled rerouting\fR  | Recommendation Q.704, \(sc\ 8)
.sp 9p
.RT
.PP
Controlled rerouting is not applicable.
.RT
.sp 1P
.LP
3.4.8
	\fISignalling point restart\fR  | Recommendation Q.704, \(sc\ 9)
.sp 9p
.RT
.PP
Signalling point restart is not applicable.
.bp
.RT
.sp 1P
.LP
3.4.9
	\fIManagement inhibiting\fR  | Recommendation Q.704, \(sc\ 10)
.sp 9p
.RT
.PP
Management inhibiting is not applicable.
.RT
.sp 1P
.LP
3.4.10
	\fISignalling traffic flow control\fR  | Recommendation Q.704, \(sc\ 11)
.sp 9p
.RT
.PP
Signalling route set congestion (Recommendation Q.704, \(sc\ 11.2.3) is 
not applicable. 
.PP
MTP User flow control (Recommendation\ Q.704, \(sc\ 11.2.7) is not
applicable.
.RT
.sp 1P
.LP
3.4.11
	\fISignalling link management\fR  | Recommendation Q.704, \(sc\ 12.2)
.sp 9p
.RT
.PP
Only basic link management procedures are
applicable.
.RT
.sp 1P
.LP
3.4.12
	\fILink set activation\fR  | Recommendation Q.704, \(sc\ 12.2.4)
.sp 9p
.RT
.PP
Link set normal activation defined in \(sc\ 12.2.4.1 is not
applicable.
.PP
Link set emergency restart is used in all cases.
.RT
.sp 1P
.LP
3.4.13
	\fITransfer prohibited\fR  | Recommendation Q.704, \(sc\ 13.2)
.sp 9p
.RT
.PP
The transfer prohibited function is not applicable. At the
reception of a TFP message, no action should be taken.
.RT
.sp 1P
.LP
3.4.14
	\fITransfer allowed\fR  | (Recommendation Q.704, \(sc 13.3)
.sp 9p
.RT
.PP
The transfer allowed function is not applicable. At the reception of a 
TFA\(hymessage, no action should be taken. 
.RT
.sp 1P
.LP
3.4.15
	\fITransfer restricted\fR  | (Recommendation Q.704, \(sc 13.4)
.sp 9p
.RT
.PP
The transfer restricted function is not applicable for the PABX. At the 
reception of the TFR message no action is taken by the PABX. 
.RT
.sp 1P
.LP
3.4.16
	\fISignalling\(hyroute\(hyset\(hytest\fR  | (Recommendation Q.704, \(sc 13.5)
.sp 9p
.RT
.PP
The signalling\(hyroute\(hyset\(hytest procedure is not applicable.
.RT
.sp 1P
.LP
3.4.17
	\fITransfer controlled\fR  | (Recommendation Q.704, \(sc\(sc 13.7, 13.8)
.sp 9p
.RT
.PP
The transfer controlled function is not applicable for the PABX. At the 
reception of the TFC message, no action is taken by PABX. 
.RT
.sp 1P
.LP
3.4.18
	\fISignalling route\(hyset\(hycongestion\(hytest\fR  | (Recommendation Q.704,
\(sc\ 13.9)
.sp 9p
.RT
.PP
The signalling route\(hyset\(hycongestion\(hytest function is not applicable 
for the PABX. 
.PP
At the reception of signalling\(hyroute\(hyset\(hycongestion\(hytest message no
action is taken by the PABX.
.RT
.sp 1P
.LP
3.4.19
	\fISignalling link test\fR  | (Recommendation Q.707, \(sc 2.2)
.sp 9p
.RT
.PP
The ability to respond to a signalling link test message with a
signalling link test acknowledge message must always be provided by the
PABX.
.RT
.sp 1P
.LP
3.5
	\fIExample of\fR 
\fI\*QScreening Function\*U\fR 
.sp 9p
.RT
.PP
\fINote\fR \ \(em\ This paragraph is provided for illustration purposes
only.
.PP
At an exchange (which has the capability of acting as an STP) each
message received on a PABX access link is passed through a \*Qscreening 
function\*U that checks that the DPC of the message is the same as the 
SP code of the 
exchange. If that is the case, the message is sent to the normal MTP message
handling functions. Otherwise, the message is discarded.
.bp
.RT
.sp 2P
.LP
\fB4\fR 	\fBInterface functions\fR 
.sp 1P
.RT
.sp 1P
.LP
4.1
	\fIGeneral\fR 
.sp 9p
.RT
.PP
The task of the interface functions is to provide the
layer\(hyto\(hylayer interfaces according to what is specified in
Recommendations\ Q.920, Q.930 on the one hand and in Recommendation\ Q.704 
on the other, see the Figure\ 2/Q.710. This will include some conversion 
functions 
which are specified in \(sc\ 4.4.
.RT
.LP
.rs
.sp 27P
.ad r
\fBFigure 2/Q.710, (MC), p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
4.2
	\fIInteractions with the network layer entity (Q.930)\fR 
.sp 9p
.RT
.PP
The layer\(hyto\(hylayer interactions between the network layer and the 
data link layer of the D\(hychannel protocol are specified in 
Recommendation\ Q.920, \(sc\ 4. The interactions are specified in the form of
primitives. The primitive applicable for the primary rate interface structure 
are: 
.RT
.LP
	DL\(hyDATA\(hyREQUEST/INDICATION
.LP
	The DL\(hyDATA\(hyREQUEST primitive is used to request that a network
layer message unit be sent. The DL\(hyDATA\(hyINDICATION indicates the
arrival of a message unit.
.sp 1P
.LP
4.3
	\fIInteractions with the message transfer part\fR 
.sp 9p
.RT
.PP
The layer\(hyto\(hylayer interactions between the MTP and the User Parts 
of Signalling System No.\ 7 are specified in Recommendations\ Q.701 and\ 
Q.704, 
Figures\ 23/Q.704 and\ 27/Q.704.
.PP
The following primitives are used:
.RT
.LP
	a)
	MTP\(hyTRANSFER (see Recommendation Q.701, \(sc 8.1),
.LP
	b)
	MTP\(hyPAUSE (see Recommendation Q.701, \(sc 8.2),
.LP
	c)
	MTP\(hyRESUME (see Recommendation Q.701, \(sc 8.3).
.bp
.sp 1P
.LP
4.4
	\fIConversion functions\fR 
.sp 9p
.RT
.PP
The Table 1/Q.710 shows the association between the D\(hychannel
primitives and the Signalling System\ No.\ 7 interactions.
.RT
.LP
.sp 2
.ce
\fBH.T. [T1.710]\fR 
.ce
TABLE\ 1/Q.710
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
lw(54p) | cw(36p) | cw(72p) .
	D\(hychannel	SS No. 7
_
.T&
lw(54p) | cw(36p) | lw(72p) .
Information transfer	DL\(hyDATA	MTP\(hyTRANSFER
_
.T&
lw(54p) | cw(36p) | lw(72p) .
Flow control	\(em  \(em	 {
MTP\(hyPAUSE (STOP)
MTP\(hyRESUME (START)
 }
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau 1/Q.710 [T1.710], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 3
.sp 1P
.LP
4.4.1
	\fIInformation transfer\fR 
.sp 9p
.RT
.PP
When receiving a DL\(hyDATA\(hyREQUEST primitive from the network layer 
entity, the interface entity generates a MTP\(hyTRANSFER Request primitive 
which contains: 
.RT
.LP
	\(em
	The message unit associated with the primitive.
.LP
	\(em
	A label consisting of DPC, OPC and SLS. The label is
generated by the interface entity on the basis of
information regarding the destination of the message. The SLS
is coded\ 0000.
.LP
	\fINote\fR \ \(em\ In some implementations where the label is not used
for routing purposes, the entire label may be coded \*Qall
zeros\*U.
.LP
	\(em
	A service information octet (SIO) is generated by the
interface entity in accordance with a predetermined rule
and, as a national option, on the basis of priority
information associated with the primitive. The NI is coded 10
or 11. The SI code is determined by the Administration or
RPOA.
.LP
	\fINote\fR \ \(em\ In the case when the interface functions provide
direct access to more than one network layer entity, the SI
code will depend on the network layer entity to which the
message is associated.
.PP
When receiving a MTP\(hyTRANSFER Indication from the MTP, the
interface entity sends a DL\(hyDATA\(hyINDICATION primitive to the network 
layer 
entity.
.sp 1P
.LP
4.4.2
	\fIFlow control\fR 
.sp 9p
.RT
.PP
When receiving a MTP\(hyPAUSE indication from the MTP, the interface entity 
will generate a DL\(hyPAUSE\(hyINDICATION primitive to the network layer 
entity.
.PP
When receiving a MTP\(hyRESUME indication from the MTP, the interface
entity will generate a DL\(hyRESUME\(hyINDICATION primitive to the network 
layer 
entity.
.RT
.LP
.rs
.sp 6P
.ad r
Blanc
.ad b
.RT
.LP
.bp
.sp 1P
.ce 1000
\v'3P'
SECTION\ 4
.ce 0
.sp 1P
.ce 1000
\fBSIGNALLING\ CONNECTION\ CONTROL\ PART\ (SCCP)\fR 
.ce 0
.sp 1P
.sp 2P
.LP
\fBRecommendation\ Q.711\fR 
.RT
.sp 2P
.sp 1P
.ce 1000
\fBFUNCTIONAL\ DESCRIPTION\ OF\ THE\ SIGNALLING\ CONNECTION\ CONTROL | 
PART\fR 
.EF '%	Fascicle\ VI.7\ \(em\ Rec.\ Q.711''
.OF '''Fascicle\ VI.7\ \(em\ Rec.\ Q.711	%'
.ce 0
.sp 1P
.LP
\fB1\fR 	\fBIntroduction\fR 
.sp 1P
.RT
.sp 1P
.LP
1.1
	\fIGeneral\fR 
.sp 9p
.RT
.PP
The Signalling Connection Control Part (SCCP) provides additional functions 
to the Message Transfer Part (MTP) to cater for both connectionless as 
well as connection\(hyoriented network services to transfer circuit related 
and non\(hycircuit related signalling information and other type of information 
between exchanges and specialized centres in telecommunication networks
(e.g.,\ for management and maintenance purposes) via a Signalling System 
No.\ 7 network. 
.PP
A functional block situated above the Message Transfer Part, the
latter being described in Recommendations\ Q.701 through Q.707, performs the
functions and procedures of the SCCP. Thus the Message Transfer Part remains
unchanged (Figure\ 1/Q.711). The combination of the MTP and the SCCP is 
called Network Service Part\ (NSP). 
.PP
The 
Network Service Part
meets the requirements for Layer\ 3
services as defined in the OSI\(hyReference Model, CCITT
Recommendation\ X.200.
.RT
.sp 1P
.LP
1.2
	\fIObjectives\fR 
.sp 9p
.RT
.PP
The overall objectives of the Signalling Connection Control Part
are to provide the means for:
.RT
.LP
	a)
	logical signalling connections within the CCITT No.\ 7
Signalling Network;
.LP
	b)
	a transfer capability for Signalling Data Units with or
without the use of logical signalling connections.
.PP
Functions of the SCCP are also used for the transfer of circuit
related and call related signalling information of the ISDN User Part with 
or without setup of end\(hyto\(hyend logical signalling connections. These 
functions are described in Recommendations\ Q.714 and Q.764. Figure\ 1/Q.711 
illustrates the 
embedding of the SCCP within the CCITT No.\ 7 signalling system.
.sp 2P
.LP
1.3
	\fIGeneral characteristic\fR 
.sp 1P
.RT
.sp 1P
.LP
1.3.1
	\fITechnique of description\fR 
.sp 9p
.RT
.PP
The Signalling Connection Control Part (SCCP) is described in terms of:
.RT
.LP
	\(em
	services provided by the SCCP,
.LP
	\(em
	services assumed from the MTP,
.LP
	\(em
	functions of the SCCP.
.PP
The functions of the SCCP are performed by means of the
SCCP\(hyprotocol between two systems which provide the NSP\(hyservice to 
the upper 
layers.
.PP
The service interfaces to the upper layers and to the MTP are
described by means of primitives and parameters, as recommended in CCITT
Recommendation\ X.200. Figure\ 2/Q.711 illustrates the relationship between 
the SCCP protocol and the adjacent services. 
.bp
.RT
.LP
.rs
.sp 25P
.ad r
\fBFigure 1/Q.711, (N), p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 18P
.ad r
\fBFigure 2/Q.711, (N), p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.sp 1P
.LP
1.3.2
	\fIPrimitives\fR 
.sp 9p
.RT
.PP
Primitives consist of commands and their respective responses
associated with the services requested of the SCCP and of the MTP, see
Figure\ 3/Q.711. The general syntax of a primitive is specified in
Recommendation\ Q.700.
.RT
.LP
.rs
.sp 35P
.ad r
\fBFigure 3/Q.711, (N), p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
1.3.3
	\fIPeer\(hyto\(hypeer communication\fR 
.sp 9p
.RT
.PP
Exchange of information between two peers of the SCCP is performed by means 
of a protocol. The protocol is a set of rules and formats by which the 
control information (and user data) is exchanged between the two peers. 
The 
protocol caters for:
.RT
.LP
	\(em
	the setup of logical signalling connections,
.LP
	\(em
	the release of logical signalling connections,
.LP
	\(em
	the transfer of data with or without logical signalling
connections.
.PP
A signalling connection is modelled in the abstract by a pair of
queues. The protocol elements are objects on that queue added by the
origination SCCP user and removed by the destination SCCP user. Each
queue represents a flow control function. Figure\ 4/Q.711 illustrates the 
modes described above. (Model for the connectionless service is for further 
study.) 
.bp
.LP
.rs
.sp 25P
.ad r
\fBFigure 4/Q.711, (N), p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
1.3.4
	\fIContents of the Recommendations Series Q.71x\fR 
.sp 9p
.RT
.PP
Recommendation Q.711 contains a general description of the services provided 
by the MTP, the services provided by the SCCP and the functions within 
the SCCP. 
.PP
Recommendation Q.712 defines the set of protocol elements and their
embedding into messages.
.PP
Recommendation Q.713 describes the formats and codes used for the SCCP 
messages. 
.PP
Recommendation Q.714 is a detailed description of the SCCP procedures as 
a protocol specification. 
.PP
Recommendation Q.716 defines and specifies values for the SCCP
performance parameters, including quality of service parameters and internal
parameters.
.RT
.sp 2P
.LP
\fB2\fR 	\fBServices provided by the SCCP\fR 
.sp 1P
.RT
.PP
The overall set of services is grouped into:
.RT
.LP
	\(em
	connection\(hyoriented services,
.LP
	\(em
	connectionless services.
.PP
Four classes of service are provided by the SCCP protocol, two for connectionless 
services and two for connection\(hyoriented services. 
.PP
The four classes are:
.RT
.LP
	0
	Basic connectionless class
.LP
	1
	Sequenced (MTP) connectionless class
.LP
	2
	Basic connection\(hyoriented class
.LP
	3
	Flow control connection\(hyoriented class
.bp
.sp 1P
.LP
2.1
	\fIConnection\(hyoriented services\fR 
.sp 9p
.RT
.PP
A distinction has to be made between:
.RT
.LP
	\(em
	temporary signalling connections,
.LP
	\(em
	permanent signalling connections.
.PP
Temporary signalling connection establishment is initiated and
controlled by the SCCP user. Temporary signalling connections are comparable
with dialled telephone connections.
.PP
Permanent signalling connections are established and controlled by the 
local (or remote) O&M\(hyfunction or by the management function of the 
node and 
they are provided for the SCCP user on a semipermanent basis. They can be
compared with leased telephone lines.
.RT
.sp 2P
.LP
2.1.1
	\fITemporary signalling connections\fR 
.sp 1P
.RT
.sp 1P
.LP
2.1.1.1
	\fIDescription\fR 
.sp 9p
.RT
.PP
The control of a signalling connection is divided into the
following phases:
.RT
.LP
	\(em
	connection establishment phase,
.LP
	\(em
	data transfer phase,
.LP
	\(em
	connection release phase.
.sp 1P
.LP
2.1.1.1.1
	\fIConnection establishment phase\fR 
.sp 9p
.RT
.PP
Connection establishment procedures provide the mechanism for
establishing temporary signalling connections between users of the SCCP.
.PP
A signalling connection between two SCCP users may consist of one or more 
connection sections. 
.PP
During connection establishment, routing functions are provided by the 
SCCP, in addition to those provided by the MTP. 
.PP
At intermediate nodes, SCCP routing determines whether a signalling
connection should be realized by one connection or by several concatenated
connection sections.
.PP
The ISDN UP may provide the routing of the request for the setup of a connection 
section. 
.PP
The connection refusal procedure is invoked if the SCCP is unable to establish 
a signalling connection. 
.RT
.sp 1P
.LP
2.1.1.1.2
	\fIData transfer phase\fR 
.sp 9p
.RT
.PP
The data transfer service provides for an exchange of user data,
called Network Service Data Units (NSDU), in either direction or in both
directions simultaneously on a signalling connection.
.PP
A SCCP message between two peer consists of:
.RT
.LP
	\(em
	Network Protocol Control Information (NPCI),
.LP
	\(em
	Network Service Data Unit (NSDU).
.PP
The Network Protocol Control Information supports the joint
operating of the SCCP\(hypeer entities within the two nodes communicating with
each other. It contains a connection reference parameter which allocates the
message to a certain signalling connection.
.PP
The Network Service Data Unit contains a certain amount of information 
from the SCCP user which has to be transferred between two nodes using 
the 
service of the SCCP.
.PP
Network Protocol Control Information and Network Service Data Unit are 
put together and transferred as a message (Figure\ 5/Q.711). If the size 
of user data is too big to be transferred within one message, user data 
are segmented into a number of portions. Each portion is mapped to a separate 
message, 
consisting of the NPCI and a NSDU (Figure\ 6/Q.711).
.PP
The data transfer service caters for sequence control and flow control 
depending on the quality of service required by the SCCP user (two different 
classes of the connection\(hyoriented service are provided by the protocol; see
Recommendation\ Q.714).
.bp
.RT
.LP
.rs
.sp 18P
.ad r
\fBFigure 5/Q.711, (N), p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 15P
.ad r
\fBFigure 6/Q.711, (N), p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
2.1.1.1.3
	\fIConnection release phase\fR 
.sp 9p
.RT
.PP
Connection release procedures provide the mechanism for
disconnecting temporary signalling connections between users of the
SCCP.
.RT
.sp 2P
.LP
2.1.1.2
	\fINetwork service primitives and parameters\fR 
.sp 1P
.RT
.sp 1P
.LP
2.1.1.2.1
	\fIOverview\fR 
.sp 9p
.RT
.PP
Table 1/Q.711 gives an overview of the primitives to the upper
layers and the corresponding parameters for the (temporary) connection 
oriented network service. Figure\ 7/Q.711 shows an overview state transition 
diagram for the sequence of primitives at a connection endpoint, refer 
to 
Recommendation\ X.213, Network Layer Service Definition of Open Systems
Interconnection for CCITT application.
.PP
A more detailed description for the primitives and their parameters is 
given in the following chapters. 
.bp
.RT
.ce
\fBH.T. [T1.711]\fR 
.ce
TABLE\ 1/Q.711
.ce
\fBNetwork service primitives for connection\(hyoriented services\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(60p) sw(60p) | cw(78p) , c | c | ^ .
Primitives	Parameters
Generic name	Specific name
_
.T&
lw(60p) | lw(60p) | lw(78p) .
N\(hyCONNECT	 {
Request
Indication
Response
Confirmation
 }	 {
Called address
Calling address
Responding address
Receipt confirmation selection
Expedited data selection
Quality of service parameter set
User data
Connection identification | ua\d\u)\d
 }
_
.T&
lw(60p) | lw(60p) | lw(78p) .
N\(hyDATA	Request Indication	 {
Confirmation request
User data
Connection identification | ua\d\u)\d
 }
_
.T&
lw(60p) | lw(60p) | lw(78p) .
N\(hyEXPEDITED DATA	Request Indication	 {
User data
Connection identification | ua\d\u)\d
 }
_
.T&
lw(60p) | lw(60p) | lw(78p) .
 {
N\(hyDATA ACKNOWLEDGE
(for further study)
 }	Request Indication	 {
Connection identification | ua\d\u)\d
 }
_
.T&
lw(60p) | lw(60p) | lw(78p) .
N\(hyDISCONNECT	Request Indication	 {
Originator
Reason
User data
Responding address
Connection identification | ua\d\u)\d
 }
_
.T&
lw(60p) | lw(60p) | lw(78p) .
N\(hyRESET	 {
Request
Indication
Response
Confirmation
 }	 {
Originator
Reason
Connection identification | ua\d\u)\d
 }
.TE
.LP

\ua\d\u)\d
In Recommendation X.213, \(sc 5.3, this parameter is
implicit.
.nr PS 9
.RT
.ad r
\fBTableau 1/Q.711 [T1.711], p. 21\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 12P
.ad r
Blanc
.ad b
.RT
.LP
.bp
.LP
.rs
.sp 47P
.ad r
\fBFigure 7/Q.711, (N), p. 22\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.sp 1P
.LP
2.1.1.2.2
	\fIConnection establishment phase\fR 
.sp 9p
.RT
.PP
A SCCP user (calling user) initiates the setup of the
connection by means of the primitive \*QN\(hyCONNECT request\*U to the 
SCCP. The SCCP entity evaluates the primitive and adds the protocol control 
information. The SCCP message (consisting of the protocol control information 
(PCI) and 
possibly an NSDU) is transmitted by means of the MTP\(hyservices to the remote
peer entity of the SCCP. It evaluates and strips the PCI and sends a primitive 
\*QN\(hyCONNECT indication\*U to the local SCCP user. On both ends of the 
connection the status \*Qpending\*U is assumed.
.PP
The called SCCP user answers with the primitive \*QN\(hyCONNECT response\*U 
to the local SCCP, which sends the response SCCP message including PCI 
to the calling SCCP. The calling SCCP sends the primitive \*QN\(hyCONNECT 
confirmation\*U to the calling SCCP\(hyUser. The connection is now ready 
for data transfer. 
.PP
The four types of N\(hyCONNECT, the request, the indication, the
response and the confirmation contain the parameters as shown and further
described in Table\ 2/Q.711.
.RT
.LP
.sp 3
.ce
\fBH.T. [T2.711]\fR 
.ce
TABLE\ 2/Q.711
.ce
\fBParameters of the primitive N\(hyCONNECT\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(60p) | cw(42p) sw(42p) sw(42p) sw(42p) , ^  | c | c | c | c.
Parameter	Primitive
	N\(hyCONNECT request	N\(hyCONNECT indication	N\(hyCONNECT response	N\(hyCONNECT confirmation
_
.T&
lw(60p) | cw(42p) | cw(42p) | lw(42p) | lw(42p) .
Called address	X	X | ud\d\u)\d		
_
.T&
lw(60p) | cw(42p) | cw(42p) | lw(42p) | lw(42p) .
Calling address	X | ud\d\u)\d	X		
_
.T&
lw(60p) | cw(42p) | cw(42p) | cw(42p) | cw(42p) .
Responding address			X	X
_
.T&
lw(60p) | cw(42p) | cw(42p) | cw(42p) | cw(42p) .
 {
Receipt confirmation selection | ua\d\u)\d
 }	X	X	X	X
_
.T&
lw(60p) | cw(42p) | cw(42p) | cw(42p) | cw(42p) .
Expedited data selection	X	X	X	X
_
.T&
lw(60p) | cw(42p) | cw(42p) | cw(42p) | cw(42p) .
 {
Quality of service parameter set
 }	X	X	X	X
_
.T&
lw(60p) | cw(42p) | cw(42p) | cw(42p) | cw(42p) .
User data | ub\d\u)\d	X	X	X	X
_
.T&
lw(60p) | cw(42p) | cw(42p) | cw(42p) | cw(42p) .
 {
Connection identification | uc\d\u)\d
 }	X	X	X	X
.TE
.LP
X
\ Parameter present within the primitive.
.LP
\ua\d\u)\d
Parameter conditionally present.
.LP
\ub\d\u)\d
User data within the connection primitives are defined as a
provider option (refer to CCITT Recommendatiom\ X.213).
.LP
\uc\d\u)\d
This parameter is not in Recommendation X.213 and is for further study.
.LP
\ud\d\u)\d
This parameter may be implicitly associated with the SCCP service access point at which this primitive is issued.
.nr PS 9
.RT
.ad r
\fBTableau 2/Q.711 [T2.711], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.PP
The parameters \*QCalled address/Calling address\*U convey addresses identifying 
the destination/source of a communication. There are three types of addresses: 
.LP
	Global Title,
.LP
	Subsystem Number,
.LP
	Signalling Point Code.
.PP
The Global Title is an address such as dialled digits which does not explicitly 
contain information that would allow routing in the signalling network, 
i.e.,\ a translation function is required. The Subsystem Number is an identification 
of a specific user function within a certain signalling point 
(SP), like the ISDN\(hyUser Part, the SCCP\(hyManagement,\ etc.
.PP
The parameter \*QResponding address\*U indicates to which destination the 
connection has been established or refused. 
.PP
The \*QResponding address\*U parameter in the 
N\(hyCONNECT primitive
conveys the address of the service access point to which the signalling
connection has been established. Under certain circumstances (e.g.\ call
redirection, generic addressing,\ etc.), the value of this parameter may be
different from the \*QCalled address\*U in the corresponding N\(hyCONNECT 
request. 
Such facilities that cause the difference are for further study.
.PP
The \*QResponding address\*U parameter is present in the N\(hyDISCONNECT
primitive only in the case where the primitive is used to indicate rejection 
of a signalling connection establishment attempt by an SCCP user function. 
The 
parameter conveys the address of the service access point from which the
N\(hyDISCONNECT\(hyrequest was issued and under circumstances like that 
mentioned 
above the \*QResponding address\*U may be different from the \*QCalled 
address\*U in 
the corresponding N\(hyCONNECT request primitive.
.PP
The parameter \*QReceipt confirmation selection\*U indicates the
use/availability of the receipt confirmation service. The need for such a
service is for further study.
.PP
The parameter \*QExpedited data selection\*U may be used to indicate
during setup whether expedited data can be transferred via the connection.
A negotiation will be performed between SCCP users, local and
remote.
.PP
The Quality of Service parameters are used during call setup to
negotiate the protocol class for the connection and, if applicable,
the flow control window size.
.PP
The N\(hyCONNECT primitives may or may not contain user data.
.PP
The parameter \*QConnection identification\*U is used to allocate a
primitive to a certain connection.
.PP
In principle, the connection establishment has to be completed
(i.e.,\ data transfer status has to be reached) before sending or receiving 
data messages. If data messages arrive at the calling user before the connection 
establishment is finished these data messages are discarded.
.PP
In addition, user data can also be transferred to/from the SCCP
within the primitives N\(hyCONNECT and N\(hyDISCONNECT.
.RT
.sp 1P
.LP
2.1.1.2.3
	\fIData transfer phase\fR 
.sp 9p
.RT
.PP
During this phase four different primitives may occur:
.RT
.LP
	a)
	N\(hyDATA (Table\ 3/Q.711),
.LP
	b)
	N\(hyEXPEDITED DATA (Table\ 4/Q.711),
.LP
	c)
	N\(hyDATA ACKNOWLEDGE,
.LP
	d)
	N\(hyRESET (Table 5/Q.711).
.PP
The primitive \*Q
N\(hyDATA
\*U (Table\ 3/Q.711) exists only as a
\*Qrequest\*U, i.e.\ from the SCCP user to the local SCCP and as an \*Qindication\*U 
at the remote end of the connection, i.e.,\ from the SCCP to the local 
SCCP user. N\(hyDATA can occur bidirectionally, i.e.,\ from the calling 
as well as the called user of the SCCP\(hyconnection. 
.PP
The parameter \*QConfirmation request\*U is used in an N\(hyDATA
primitive to indicate the need to confirm the receipt of the N\(hyDATA 
primitive by the remote SCCP user. The confirmation may be given by the 
N\(hyDATA 
ACKNOWLEDGE primitive. Receipt confirmation is provided only on connections
which get the Receipt Confirmation facility during setup. The matter is for
further study.
.PP
The primitive \*Q
N\(hyEXPEDITED DATA
\*U (Table\ 4/Q.711) may be used by the SCCP user only, if the signalling 
connection is set up according to a 
class providing the capability to transfer expedited data (refer to
Recommendation\ Q.714).
.bp
.RT
.ce
\fBH.T. [T3.711]\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(168p) .
TABLE\ 3/Q.711
.T&
cw(168p) .
 {
\fBParameters of the primitive N\(hyDATA\fR
 }
.T&
cw(84p) | cw(42p) sw(42p) , ^  | c | c.
Parameter	Primitive
	N\(hyDATA request	N\(hyDATA indication
_
.T&
lw(84p) | cw(42p) | cw(42p) .
 {
Confirmation request | ua\d\u)\d
 }	X	X
_
.T&
lw(84p) | cw(42p) | cw(42p) .
User data	X	X
_
.T&
lw(84p) | cw(42p) | cw(42p) .
 {
Connection identification | ub\d\u)\d
 }	X	X
.TE
.LP
X
\ Parameter present within the primitive.
.LP
\ua\d\u)\d
Parameter conditionally present.
.LP
\ub\d\u)\d
This parameter is for further study.
.nr PS 9
.RT
.ad r
\fBTableau 3/Q.711 [T3.711], p. 24\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 5
.ce
\fBH.T. [T4.711]\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(168p) .
TABLE\ 4/Q.711
.T&
cw(168p) .
 {
\fBParameters of the primitive N\(hyEXPEDITED DATA\fR
 }
.T&
cw(84p) | cw(42p) sw(42p) , ^  | c | c.
Parameter	Primitive
	N\(hyEXPEDITED DATA request	 {
N\(hyEXPEDITED DATA indication
 }
_
.T&
lw(84p) | cw(42p) | cw(42p) .
User data	X	X
_
.T&
lw(84p) | cw(42p) | cw(42p) .
 {
Connection identification | ua\d\u)\d
 }	X	X
.TE
.LP
X
\ Parameter present within the primitive.
.LP
\ua\d\u)\d
This parameter is for further study.
.nr PS 9
.RT
.ad r
\fBTableau 4/Q.711 [T4.711], p. 25\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.rs
.sp 4P
.ad r
Blanc
.ad b
.RT
.LP
.bp
.PP
The primitive \*QN\(hyDATA ACKNOWLEDGE\*U is used when the delivery
confirmation service is selected. This primitive is for further study.
.PP
The 
primitive N\(hyRESET
(Table 5/Q.711) can occur in the data
transfer state of a connection with a protocol class including flow control.
N\(hyRESET overrides all other activities and causes the SCCP to start a
re\(hyinitialization procedure for sequence numbering. N\(hyRESET appears as a
request, an indication, a response and a confirmation. After reception of a
N\(hyRESET request and before the sending of a N\(hyRESET confirmation, 
all NSDUs 
from SCCP are discarded by th SCCP.
.RT
.LP
.sp 2
.ce
\fBH.T. [T5.711]\fR 
.ce
TABLE\ 5/Q.711
.ce
\fBParameters of the primitive N\(hyRESET\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(60p) | cw(42p) sw(42p) sw(42p) sw(42p) , ^  | c | c | c | c.
Parameter	Primitive
	N\(hyRESET  request	N\(hyRESET  indication	N\(hyRESET  response	N\(hyRESET  confirmation
_
.T&
lw(60p) | lw(42p) | cw(42p) | lw(42p) | lw(42p) .
Originator		X		
_
.T&
lw(60p) | cw(42p) | cw(42p) | lw(42p) | lw(42p) .
Reason	X	X		
_
.T&
lw(60p) | cw(42p) | cw(42p) | cw(42p) | cw(42p) .
 {
Connection identification | ua\d\u)\d
 }	X	X	X	X
.TE
.LP
X
\ Parameter present within the primitive.
.LP
\ua\d\u)\d
This parameter is for further study.
.nr PS 9
.RT
.ad r
\fBTableau 5/Q.711 [T5.711], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 3
.PP
The parameter \*QOriginator\*U indicates the source of the reset and can 
be any of the following: the \*Qnetwork service provider\*U (network 
originated), the \*Qnetwork service user\*U (user originated), or \*Qundefined\*U. 
The parameter \*QReason\*U indicates \*Qnetwork service provider congestion\*U, 
\*Qreason 
unspecified\*U or \*Qlocal SCCP originated\*U for a network originated 
reset, and 
indicates \*Quser synchronization\*U for a user originated reset. The \*QReason\*U 
parameter is \*Qundefined\*U when the \*QOriginator\*U parameter is \*Qundefined\*U. 
.sp 1P
.LP
2.1.1.2.4
	\fIRelease phase\fR 
.sp 9p
.RT
.PP
The primitives for the release phase are 
N\(hyDISCONNECT
request and N\(hyDISCONNECT indication. These primitives are also used for the
connection refusal during connection establishment phase. Parameters are
included to notify the reason for connection release/refusal and the initiator 
of the connection release/refusal procedure. User data may be also be included 
(see Table\ 6/Q.711). 
.RT
.PP
The parameter \*QOriginator\*U indicates the initiator of the
connection release or the connection refusal. It may assume the following
values:
.LP
	\(em
	the network service provider,
.LP
	\(em
	the network service user,
.LP
	\(em
	undefined.
.bp
.ce
\fBH.T. [T6.711]\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(168p) .
TABLE\ 6/Q.711
.T&
cw(168p) .
 {
\fBParameters of the primitive N\(hyDISCONNECT\fR
 }
.T&
cw(84p) | cw(42p) sw(42p) , ^  | c | c.
Parameter	Primitive
	N\(hyDISCONNECT request	N\(hyDISCONNECT indication
_
.T&
lw(84p) | lw(42p) | cw(42p) .
Originator		X
_
.T&
lw(84p) | cw(42p) | cw(42p) .
Responding address	X	X
_
.T&
lw(84p) | cw(42p) | cw(42p) .
Reason	X	X
_
.T&
lw(84p) | cw(42p) | cw(42p) .
User data	X	X
_
.T&
lw(84p) | cw(42p) | cw(42p) .
 {
Connection identification | ua\d\u)\d
 }	X	X
.TE
.LP
X
\ Parameter present within the primitive.
.LP
\ua\d\u)\d
This parameter is for further study.
.nr PS 9
.RT
.ad r
\fBTableau 6/Q.711 [T6.711], p.\fR 
.sp 1P
.RT
.ad b
.RT
.PP
.sp 5
The parameter \*QReason\*U gives information about the cause of the
connection release or the connection refusal. It may assume any of the
following values in accordance with the value of the \*QOriginator\*U:
.LP
These values may be used locally at the originating/initiating
node as an implementation option.
.FE
It is noted that the term \*Qconnection rejection\*U is used in
Recommendation X.213 for the \*QReason\*U parameter values.
.FE
.LP
	1)
	When the \*QOriginator\*U parameter indicates the
\*Qnetwork service provider\*U:
.LP
	\(em
	disconnection \(em abnormal condition of non\(hytransient
nature;
.LP
	\(em
	disconnection \(em abnormal condition of transient
nature;
.LP
	\(em
	disconnection \(em invalid state
;
.LP
	\(em
	disconnection \(em release in progress
;
.LP
	\(em
	connection refusal
\(em destination address
unknown (non\(hytransient condition)
;
.LP
	\(em
	connection refusal
\(em destination
inaccessible/non\(hytransient condition
;
.LP
	\(em
	connection refusal
\(em destination
inaccessible/transient condition
;
.LP
	\(em
	connection refusal
\(em QOS not
available/non\(hytransient condition
;
.LP
	\(em
	connection refusal
\(em QOS not
available/transient condition
;
.LP
	\(em
	connection refusal
\(em reason
unspecified/non\(hytransient condition
;
.LP
	\(em
	connection refusal
\(em reason unspecified/transient
condition
;
.LP
	\(em
	connection refusal
\(em local error
;
.LP
	\(em
	connection refusal
\(em invalid state
;
.LP
	\(em
	connection refusal
\(em no translation
;
.LP
	\(em
	connection refusal
\(em in restart
phase
.
.LP
.sp 1
.bp
.LP
	2)
	When the \*QOriginator\*U parameter indicates the \*Qnetwork
\fR 
service user\*U:
.LP
	\(em
	disconnection \(em normal condition;
.LP
	\(em
	disconnection \(em abnormal condition;
.LP
	\(em
	disconnection \(em end user congestion;
.LP
	\(em
	disconnection \(em end user failure;
.LP
	\(em
	disconnection \(em SCCP user originated;
.LP
	\(em
	disconnection \(em access congestion;
.LP
	\(em
	disconnection \(em access failure;
.LP
	\(em
	disconnection \(em subsystem congestion;
.LP
	\(em
	connection refusal
\(em non\(hytransient condition;
.LP
	\(em
	connection refusal
\(em transient condition;
.LP
	\(em
	connection refusal
\(em incompatible information in
NSDUs;
.LP
	\(em
	connection refusal
\(em end user originated;
.LP
	\(em
	connection refusal
\(em end user congestion;
.LP
	\(em
	connection refusal
\(em end user failure;
.LP
	\(em
	connection refusal
\(em SCCP user originated;
.LP
	\(em
	connection refusal
\(em access congestion;
.LP
	\(em
	connection refusal
\(em access failure;
.LP
	\(em
	connection refusal
\(em subsystem congestion.
.LP
	3)
	When the \*QOriginator\*U parameter is \*Qundefined\*U, then the
\*QReason\*U parameter is also \*Qundefined\*U.
.PP
\fINote\fR \ \(em\ Addition to, or refinement of, this list of possible
values for the parameter \*QReason\*U to convey more specific diagnostic, 
cause and management information is for further study. 
.sp 1P
.LP
2.1.1.3
	\fIAdditional SCCP primitive and interface elements\fR 
.sp 9p
.RT
.PP
In addition to those primitives in Recommendation X.213, there is a primitive 
N\(hyINFORM needed by the SCCP connection\(hyoriented services during data 
transfer phase. There are also three interface elements used by User Part 
Type\ A, e.g.\ ISDN\(hyUP, as in Figure\ 1/Q.711.
.RT
.sp 1P
.LP
2.1.1.3.1
	\fINotice service\fR 
.sp 9p
.RT
.PP
The provision of the notice service by use of the \*QN\(hyINFORM\*U
primitive is for further study.
.PP
The 
primitive N\(hyINFORM
(Table 7/Q.711) is used during data
transfer to convey relevant network/user information. The primitive \*QN\(hyINFORM\*U 
will contain the parameters \*QReason', \*QConnection Identification\*U 
and \*QQOS 
parameter set\*U.
.RT
.PP
The primitive \*QN\(hyINFORM request\*U is provided to inform the SCCP 
of the connection user failure/congestion, or anticipated QOS changes. 
A further primitive \*QN\(hyINFORM indication\*U is provided to indicate 
actual failures of the SCCP to the SCCP\(hyuser functions or anticipated 
quality of service changes or 
other indications to the SCCP\(hyuser functions.
.PP
The parameter \*QReason\*U contains the network/user information to be
conveyed. It may assume the following values:
.RT
.LP
	\(em
	network service provider failure;
.LP
	\(em
	network service congestion;
.LP
	\(em
	network service provider QOS change;
.LP
	\(em
	network service user failure;
.LP
	\(em
	network service user congestion;
.LP
	\(em
	network service user QOS change;
.LP
	\(em
	reason unspecified.
.bp
.ce
\fBH.T. [T7.711]\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(168p) .
TABLE\ 7/Q.711
.T&
cw(168p) .
 {
\fBParameters of the primitive N\(hyINFORM\fR
 }
.T&
cw(84p) | cw(42p) sw(42p) , ^  | c | c.
Parameter	Primitive
	N\(hyINFORM  request	N\(hyINFORM indication
_
.T&
lw(84p) | cw(42p) | cw(42p) .
Reason	X	X
_
.T&
lw(84p) | cw(42p) | cw(42p) .
 {
Connection identification | ua\d\u)\d
 }	X	X
_
.T&
lw(84p) | cw(42p) | cw(42p) .
QOS parameter set | ua\d\u)\d	X	X
.TE
.LP
X
\ Parameter present within the primitive.
.LP
\ua\d\u)\d
Parameter is for further study.
.nr PS 9
.RT
.ad r
\fBTableau 7/Q.711 [T7.711], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 3
.sp 1P
.LP
2.1.1.3.2
	\fIConnection establishment interface elements\fR 
.sp 9p
.RT
.PP
For the User Part Type\ A in Figure\ 1/Q.711, two mechanisms are
available to set up a signalling connection. For example, the ISDN\(hyUser Part
may use the mechanism described in \(sc\ 2.1.1.2.2 or may request the SCCP to
initiate a connection and return the information to the ISDN\(hyUser Part for
transmission within an ISDN\(hyUser\(hyPart call setup message, like an Initial
Address Message (IAM).
.PP
Three interface elements are defined for the information flow between SCCP 
and ISDN\(hyUser Part: 
.RT
.LP
	a)
	REQUEST to the SCCP, Type 1 and Type 2;
.LP
	b)
	REPLY from the SCCP.
.PP
The 
REQUEST Type 1
contains the following
parameters:
.LP
	\(em
	connection identification (for further study);
.LP
	\(em
	receipt confirmation selection;
.LP
	\(em
	expedited data selection;
.LP
	\(em
	quality of service parameter set.
.PP
The 
REQUEST Type 2
contains the following
parameters:
.LP
	\(em
	protocol class;
.LP
	\(em
	credit;
.LP
	\(em
	connection identification (for further study);
.LP
	\(em
	source local reference;
.LP
	\(em
	originating signalling point code;
.LP
	\(em
	reply request;
.LP
	\(em
	refusal indicator.
.PP
The 
REPLY
contains the following parameters:
.LP
	\(em
	source local reference;
.LP
	\(em
	protocol class;
.LP
	\(em
	credit;
.LP
	\(em
	connection identification (for further study).
.bp
.sp 2P
.LP
2.1.2
	\fIPermanent signalling connections\fR 
.sp 1P
.RT
.sp 1P
.LP
2.1.2.1
	\fIDescription\fR 
.sp 9p
.RT
.PP
The setup/release service is controlled by the Administration
(e.g.\ O&M application). The functions for setup and release may be similar
to those provided for temporary signalling connections and are for further
study. The classes of service are the same.
.PP
Permanently established signalling connections may require additional safeguarding 
mechanisms within the endpoints (relaypoints) of the connection in order 
to guarantee their re\(hyestablishment in case of a processor outage 
followed by a recovery.
.RT
.sp 1P
.LP
2.1.2.2
	\fIPrimitives and parameters\fR 
.sp 9p
.RT
.PP
The primitives and their parameters are listed in Table\ 8/Q.711.
Their content and functionality correspond to the description within
\(sc\ 2.1.1.2.3.
.RT
.ce
\fBH.T. [T8.711]\fR 
.ce
TABLE\ 8/Q.711
.ce
\fBPrimitives for the data transfer on\fR 
.ce
\fBpermanent connections\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(60p) sw(60p) | cw(78p) , c | c | ^ .
Primitives	Parameters
Generic Name	Specific Name
_
.T&
lw(60p) | lw(60p) | lw(78p) .
N\(hyDATA	Request Indication	 {
Confirmation request
User data
Connection identification | ua\d\u)\d
 }
_
.T&
lw(60p) | lw(60p) | lw(78p) .
N\(hyEXPEDITED DATA	Request Indication	 {
User data
Connection identification | ua\d\u)\d
 }
_
.T&
lw(60p) | lw(60p) | lw(78p) .
 {
N\(hyDATA ACKNOWLEDGE
(for further study)
 }	Request Indication	 {
Connection identification | ua\d\u)\d
 }
_
.T&
lw(60p) | lw(60p) | lw(78p) .
N\(hyRESET	 {
Request
Indication
Response
Confirmation
 }	 {
Originator
Reason
Connection identification | ua\d\u)\d
 }
.TE
.LP

\ua\d\u)\d
Parameter is for further study.
.nr PS 9
.RT
.ad r
\fBTableau 8/Q.711 [T8.711], p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
2.2
	\fIConnectionless services\fR 
.sp 9p
.RT
.PP
The SCCP provides the SCCP user with the ability to transfer
signalling messages via the signalling network without setup of a signalling
connection. In addition to the MTP capability, a \*QRouting\*U function 
has to be provided within the SCCP, which maps the called address to the 
Signalling Point Codes of the MTP Service. 
.PP
This mapping function may be provided within each node or might be
distributed over the network or could be provided in some special translation 
centres. 
.PP
Under certain conditions of congestion and unavailability of
subsystems and/or signalling points, connectionless messages could be discarded 
instead of being delivered. If the SCCP user wishes to be informed of the 
non\(hydelivery of messages, the Return Option parameter must be set to 
\*Qreturn 
message on error\*U in the primitive to the SCCP.
.bp
.RT
.sp 1P
.LP
2.2.1
	\fIDescription\fR 
.sp 9p
.RT
.PP
There are two possibilities to transfer data without a connection setup 
with regard to the sequence control mechanisms provided by the 
MTP.
.RT
.LP
	a)
	The MTP guarantees (to a high degree of probability) an
in\(hysequence delivery of messages which contain the same
Signalling Link Selection (SLS) code. The SCCP user can demand
this MTP service by allocating a parameter \*QSequence control\*U
into the primitive to the SCCP. The SCCP will put the same
SLS code into the primitive to the MTP for all primitives from
the SCCP user with the same \*QSequence control\*U parameter.
.LP
	b)
	If the in\(hysequence delivery is not required, the SCCP can
insert SLS codes randomly or with respect to appropriate load
sharing within the signalling network.
.PP
The rules to achieve load sharing are not defined in the SCCP
Recommendations.
.sp 2P
.LP
2.2.2
	\fIPrimitives and parameters of the connectionless service\fR 
.sp 1P
.RT
.sp 1P
.LP
2.2.2.1
	\fIOverview\fR 
.sp 9p
.RT
.PP
Table 9/Q.711 gives an overview of the primitives to the upper
layers and the corresponding parameters for the connectionless
service.
.RT
.LP
.sp 1
.ce
\fBH.T. [T9.711]\fR 
.ce
TABLE\ 9/Q.711
.ce
\fBPrimitives and parameters of the connectionless service\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(60p) sw(60p) | cw(78p) , c | c | ^ .
Primitives	Parameters
Generic Name	Specific Name
_
.T&
lw(60p) | lw(60p) | lw(78p) .
N\(hyUNITDATA	Request Indication	 {
Called address
Calling address
Sequence control | ua\d\u)\d
Return option | ua\d\u)\d
User data
 }
_
.T&
lw(60p) | lw(60p) | lw(78p) .
N\(hyNOTICE	Indication	 {
Called address
Calling address
Reason for return
User data
 }
.TE
.LP

\ua\d\u)\d
An integration of the parameter Sequence control/Return option
into the Quality of Service parameter set is for further study.
.nr PS 9
.RT
.ad r
\fBTableau 9/Q.711 [T9.711], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 2
.sp 2P
.LP
2.2.2.2
	\fIParameters\fR 
.sp 1P
.RT
.sp 1P
.LP
2.2.2.2.1
	\fIAddress\fR 
.sp 9p
.RT
.PP
The parameters \*QCalled address\*U and \*QCalling address\*U serve to
identify the destination and origination respectively, of the connectionless
message. These parameters may contain some combination of global titles,
subsystem numbers, and signalling point codes.
.bp
.RT
.sp 1P
.LP
2.2.2.2.2
	\fISequence control\fR 
.sp 9p
.RT
.PP
The parameter \*QSequence control\*U indicates to the SCCP whether the 
user wishes the service \*Qsequence guaranteed\*U or the service \*Qsequence 
not 
guaranteed\*U. In the case of \*Qsequence guaranteed\*U service, this parameter 
is an indication to the SCCP that a given stream of messages with the same 
called 
address has to be delivered in sequence by making use of the features of the
MTP. In addition, this parameter is also used to distinguish different 
streams of messages so that the SCCP can allocate SLS codes appropriately 
to help the MTP in achieving an even distribution of signalling traffic. 
.RT
.sp 1P
.LP
2.2.2.2.3
	\fIReturn option\fR 
.sp 9p
.RT
.PP
The parameter \*QReturn option\*U is used to determine the handling of 
messages encountering transport problems. 
.PP
\*QReturn option\*U may assume the following values:
.RT
.LP
	\(em
	discard message on error;
.LP
	\(em
	return message on error.
.sp 1P
.LP
2.2.2.2.4
	\fIReason for return\fR 
.sp 9p
.RT
.PP
The parameter \*QReason for return\*U identifies the reason why a
message was not able to be delivered to its final destination.
.PP
\*QReason for return\*U may assume the following values:
.RT
.LP
	\(em
	no translation for an address of such nature;
.LP
	\(em
	no translation for this specific address;
.LP
	\(em
	subsystem configuration;
.LP
	\(em
	subsystem failure;
.LP
	\(em
	unequipped user;
.LP
	\(em
	network congestion;
.LP
	\(em
	network failure.
.sp 1P
.LP
2.2.2.2.5
	\fIUser data\fR 
.sp 9p
.RT
.PP
The parameter \*QUser data\*U is information which is to be transferred 
transparently between SCCP users. 
.RT
.sp 2P
.LP
2.2.2.3
	\fIPrimitives\fR 
.sp 1P
.RT
.sp 1P
.LP
2.2.2.3.1
	\fIUNITDATA\fR 
.sp 9p
.RT
.PP
The \*QN\(hyUNITDATA request\*U primitive is the means by which a SCCP
user requests the SCCP to transport data to another user.
.PP
The \*QN\(hyUNITDATA indication\*U primitive informs a user that data is
being delivered to it from the SCCP.
.PP
Table 10/Q.711 indicates the parameters of the 
primitive
N\(hyUNITDATA
.
.RT
.sp 1P
.LP
2.2.2.3.2
	\fINOTICE\fR 
.sp 9p
.RT
.PP
The \*QN\(hyNOTICE indication\*U primitive is the means by which the SCCP 
returns to the originating user a message which could not reach the final 
destination.
.PP
Table 11/Q.711 indicates the parameters of the 
primitive
N\(hyNOTICE
.
.bp
.RT
.ce
\fBH.T. [T10.711]\fR 
.ce
TABLE\ 10/Q.711
.ce
\fBParameters of the primitive N\(hyUNITDATA\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(72p) | cw(42p) sw(42p) , ^  | c | c.
Parameter	Primitive
	N\(hyUNITDATA  request	N\(hyUNITDATA  indication
_
.T&
lw(72p) | cw(42p) | cw(42p) .
Called address	X	X
_
.T&
lw(72p) | cw(42p) | cw(42p) .
Calling address	X	X
_
.T&
lw(72p) | cw(42p) | cw(42p) .
Sequence control | ua\d\u)\d	X	
_
.T&
lw(72p) | cw(42p) | cw(42p) .
Return option	X	
_
.T&
lw(72p) | cw(42p) | cw(42p) .
User data	X	X
.TE
.LP
\ua\d\u)\d
The inclusion of this parameter in the N\(hyUNITDATA indication
primitive is for further study.
.nr PS 9
.RT
.ad r
\fBTableau 10/Q.711 [T10.711], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 6
.ce
\fBH.T. [T11.711]\fR 
.ce
TABLE\ 11/Q.711
.ce
\fBParameters of the primitive N\(hyNOTICE\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(72p) | cw(48p) , ^  | c.
Parameter	Primitive
	N\(hyNOTICE  indication
_
.T&
lw(72p) | cw(48p) .
Called address	X
_
.T&
lw(72p) | cw(48p) .
Calling address	X
_
.T&
lw(72p) | cw(48p) .
Reason for return	X
_
.T&
lw(72p) | cw(48p) .
User data	X
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau 11/Q.711 [T11.711], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.bp
.sp 2P
.LP
2.3
	\fISCCP management\fR 
.sp 1P
.RT
.sp 1P
.LP
2.3.1
	\fIDescription\fR 
.sp 9p
.RT
.PP
The SCCP provides SCCP management procedures (see
Recommendation\ Q.714, \(sc\ 5) to maintain network performances by rerouting 
or 
throttling traffic in the event of failure or congestion in the network. 
These SCCP management procedures apply to both the connection\(hyoriented 
and the 
connectionless services of the SCCP.
.RT
.sp 2P
.LP
2.3.2
	\fIPrimitives and parameters of the SCCP management\fR 
.sp 1P
.RT
.sp 1P
.LP
2.3.2.1
	\fIOverview\fR 
.sp 9p
.RT
.PP
Table 12/Q.711 gives an overview of the primitives to the upper
layers and the corresponding parameters for the SCCP management.
.RT
.ce
\fBH.T. [T12.711]\fR 
.ce
TABLE\ 12/Q.711
.ce
\fBPrimitives and parameters of the SCCP management\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(60p) sw(60p) | cw(90p) , c | c | ^ .
Primitives	Parameters
Generic Name	Specific Name
_
.T&
lw(60p) | lw(60p) | lw(90p) .
R\(hyCOORD	 {
Request
Indication
Response
Confirmation
 }	 {
Affected subsystem
Subsystem multiplicity indicator
 }
_
.T&
lw(60p) | lw(60p) | lw(90p) .
N\(hySTATE	Request Indication	 {
Affected subsystem
User status
Subsystem multiplicity indicator
 }
_
.T&
lw(60p) | lw(60p) | lw(90p) .
N\(hyPCSTATE	Indication	 {
Affected DPC
Signalling Point Status
\fBH.T. [T13.711]\fR
 }
_
.T&
rw(60p) | cw(60p) | lw(90p) .
	TABLE\ 13/Q.711	
.T&
cw(60p) | cw(60p) | lw(90p) .
 {
\fBParameters of the primitive N\(hyCOORD\fR
 }		
.T&
cw(84p) | cw(36p) sw(36p) sw(36p) sw(36p) , ^  | c | c | c | c.
Parameter	Primitive
	N\(hyCOORD  request	N\(hyCOORD  indication	N\(hyCOORD  response	N\(hyCOORD  confirmation
_
.T&
lw(84p) | cw(36p) | cw(36p) | cw(36p) | cw(36p) .
Affected subsystem	X	X	X	X
_
.T&
lw(84p) | cw(36p) | cw(36p) | cw(36p) | cw(36p) .
 {
Subsystem multiplicity indicator
 }		X		X
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau 12/Q.711 [T12.711], p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 2P
.LP
2.3.2.2
	\fIParameters\fR 
.sp 1P
.RT
.sp 1P
.LP
2.3.2.2.1
	\fIAddress\fR 
.sp 9p
.RT
.PP
See \(sc 2.2.2.2.1.
.RT
.sp 1P
.LP
2.3.2.2.2
	\fIAffected subsystem\fR 
.sp 9p
.RT
.PP
The parameter \*QAffected subsystem\*U identifies a user which is
failed, withdrawn, congested, or allowed. The \*QAffected subsystem\*U 
parameter 
contains the same type of information as the \*QCalled address\*U and \*QCalling 
address\*U.
.RT
.sp 1P
.LP
2.3.2.2.3
	\fIUser status\fR 
.sp 9p
.RT
.PP
The parameter \*QUser status\*U is used to inform a SCCP user of the
status of the affected subsystem.
.PP
\*QUser status\*U may assume one of the following values:
.RT
.LP
	\(em
	User\(hyin\(hyservice (UIS);
.LP
	\(em
	User\(hyout\(hyof\(hyservice (UOS).
.bp
.sp 1P
.LP
2.3.2.2.4
	\fISubsystem multiplicity indicator\fR 
.sp 9p
.RT
.PP
The parameter \*QSubsystem multiplicity indicator\*U identifies the
number of replications of a subsystem.
.RT
.sp 1P
.LP
2.3.2.2.5
	\fIAffected DPC\fR 
.sp 9p
.RT
.PP
The parameter \*QAffected DPC\*U identifies a signalling point which
is failed, congested, or allowed. The \*QAffected DPC\*U parameter contains 
unique identification of a signalling point. 
.RT
.sp 1P
.LP
2.3.2.2.6
	\fISignalling point status\fR 
.sp 9p
.RT
.PP
The parameter \*QSignalling point status\*U is used to inform a user of 
the status of an affected DPC. 
.PP
\*QSignalling point status\*U may assume the following values:
.RT
.LP
	\(em
	Signalling point inaccessible,
.LP
	\(em
	Signalling point congested,
.LP
	\(em
	Signalling point accessible.
.sp 2P
.LP
2.3.2.3
	\fIPrimitives\fR 
.sp 1P
.RT
.sp 1P
.LP
2.3.2.3.1
	\fICOORD\fR 
.sp 9p
.RT
.PP
The 
\*QN\(hyCOORD\*U primitive
(Table 13/Q.711) is used by
replicated subsystems to coordinate the withdrawal of one of the
subsystems.
.PP
The primitive exists as: a \*Qrequest\*U when the originating user is
requesting permission to go out of service; an \*Qindication\*U when the 
request to go out of service is delivered to the originator's replicate; 
a \*Qresponse\*U when the originator's replicate announced it has sufficient 
resources 
to let the originator go out of service; and as a \*Qconfirmation\*U
when the originator is informed that it may go out of service.
.RT
.ce
\fBH.T. [T13.711]\fR 
.ce
TABLE\ 13/Q.711
.ce
\fBParameters of the primitive N\(hyCOORD\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(84p) | cw(36p) sw(36p) sw(36p) sw(36p) , ^  | c | c | c | c.
Parameter	Primitive
	N\(hyCOORD  request	N\(hyCOORD  indication	N\(hyCOORD  response	N\(hyCOORD  confirmation
_
.T&
lw(84p) | cw(36p) | cw(36p) | cw(36p) | cw(36p) .
Affected subsystem	X	X	X	X
_
.T&
lw(84p) | cw(36p) | cw(36p) | cw(36p) | cw(36p) .
 {
Subsystem multiplicity indicator
 }		X		X
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau 13/Q.711 [T13.711], p.\fR 
.sp 1P
.RT
.ad b
.RT
.sp 1P
.LP
2.3.2.3.2
	\fISTATE\fR 
.sp 9p
.RT
.PP
The \*Q
N\(hySTATE request\*U primitive
(Table 14/Q.711) is used to inform the SCCP management about the status 
of the originating user. The 
\*QN\(hySTATE indication\*U primitive is used to inform an SCCP user
accordingly.
.bp
.RT
.ce
\fBH.T. [T14.711]\fR 
.ce
TABLE\ 14/Q.711
.ce
\fBParameters of the primitive N\(hySTATE\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(84p) | cw(42p) sw(42p) , ^  | c | c.
Parameter	Primitive
	N\(hySTATE  request	N\(hySTATE  indication
_
.T&
lw(84p) | cw(42p) | cw(42p) .
Affected subsystem	X	X
_
.T&
lw(84p) | cw(42p) | cw(42p) .
User status	X	X
_
.T&
lw(84p) | cw(42p) | cw(42p) .
 {
Subsystem multiplicity indicator
 }		X
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau 14/Q.711 [T14.711], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 1
.sp 1P
.LP
2.3.2.3.3
	\fIPCSTATE\fR 
.sp 9p
.RT
.PP
The \*Q
N\(hyPCSTATE primitive
\*U (Table 15/Q.711) is used to
inform a user about the status of a signalling point.
.RT
.ce
\fBH.T. [T15.711]\fR 
.ce
TABLE\ 15/Q.711
.ce
\fBParameters of the primitive N\(hyPCSTATE\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(72p) | cw(48p) , ^  | c.
Parameter	Primitive
	N\(hyPCSTATE  indication
_
.T&
lw(72p) | cw(48p) .
Affectedd DPC	X
_
.T&
lw(72p) | cw(48p) .
Signalling Point Status	X
_
.TE
.nr PS 9
.RT
.ad r
\fBTableau 15/Q.711 [T15.711], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 1
.sp 2P
.LP
\fB3\fR 	\fBServices assumed from the MTP\fR 
.sp 1P
.RT
.sp 1P
.LP
3.1
	\fIDescription\fR 
.sp 9p
.RT
.PP
This paragraph describes the functional interface offered by the
MTP to the upper layer functions, i.e.,\ the SCCP and the User Parts. In 
order to align the terminology with the OSI\(hyModel, the description uses 
the terms 
\*Qprimitives\*U and \*Qparameters\*U.
.bp
.RT
.sp 1P
.LP
3.2
	\fIPrimitives and parameters\fR 
.sp 9p
.RT
.PP
The primitives and parameters are shown in Table\ 16/Q.711.
.RT
.LP
.sp 4
.ce
\fBH.T. [T16.711]\fR 
.ce
TABLE\ 16/Q.711
.ce
\fBMessage transfer part service primitives\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(60p) sw(60p) | cw(60p) , c | c | ^ .
Primitives	Parameters
Generic Name	Specific Name
_
.T&
lw(60p) | lw(60p) | lw(60p) .
MTP\(hyTRANSFER	Request Indication	OPC DPC SLS SIO User Data
_
.T&
lw(60p) | lw(60p) | lw(60p) .
MTP\(hyPAUSE (Stop)	Indication	Affected DPC
_
.T&
lw(60p) | lw(60p) | lw(60p) .
MTP\(hyRESUME (Start)	Indication	Affected DPC
_
.T&
lw(60p) | lw(60p) | lw(60p) .
MTP\(hySTATUS	Indication	 {
Affected DPC
Cause | ua\d\u)\d
 }
.TE
.LP

\ua\d\u)\d
The cause parameter has, at present, two values:
.LP
\fBi\fR
i)
\fISignalling network congested (level)\fR
.LP
This level value is applicable if national option with congestion priorities and multiple signalling link states without congestion priorities as in Recommendation\ Q.704 is implemented.
.LP
ii)
\fIRemote user unavailable.\fR
.nr PS 9
.RT
.ad r
\fBTableau 16/Q.711 [T16.711], p.\fR 
.sp 1P
.RT
.ad b
.RT
.LP
.sp 5
.sp 1P
.LP
3.2.1
	\fITRANSFER\fR 
.sp 9p
.RT
.PP
The primitive \*QMTP\(hyTRANSFER\*U is used between level 4 and level\ 3
(SMH) to provide the MTP message transfer service.
.RT
.sp 1P
.LP
3.2.2
	\fIPAUSE\fR 
.sp 9p
.RT
.PP
The primitive \*QMTP\(hyPAUSE\*U indicates to the SCCP total inability
of providing the MTP service to the specified destination.
.PP
This primitive corresponds to the destination inaccessible state as
defined in Recommendation\ Q.704.
.bp
.RT
.sp 1P
.LP
3.2.3
	\fIRESUME\fR 
.sp 9p
.RT
.PP
The primitive \*QMTP\(hyRESUME\*U indicates to the SCCP total ability of 
providing the MTP service to the specified destination. 
.PP
This primitive corresponds to the destination accessible state as
defined in Recommendation\ Q.704.
.RT
.sp 1P
.LP
3.2.4
	\fISTATUS\fR 
.sp 9p
.RT
.PP
The primitive \*QMTP\(hySTATUS\*U indicates to the SCCP partial inability 
of providing the MTP service to the specified destination, or the 
unavailability of the remote peer user. The response of the SCCP for the 
latter case is for further study. 
.PP
In the case of national option with congestion priorities and multiple 
signalling link congestion states without priorities as in Recommendation\ 
Q.704 is implemented, this \*QMTP\(hySTATUS\*U primitive is also used to 
indicate a change of congestion level. 
.PP
This primitive corresponds to the destination congested state as
defined in Recommendation\ Q.704.
.RT
.sp 2P
.LP
\fB4\fR 	\fBFunctions provided by the SCCP\fR 
.sp 1P
.RT
.PP
This section is an overview of the functional blocks within the
SCCP.
.RT
.sp 2P
.LP
4.1
	\fIConnection\(hyoriented functions\fR 
.sp 1P
.RT
.sp 1P
.LP
4.1.1
	\fIFunctions for temporary signalling connections\fR 
.sp 9p
.RT
.sp 1P
.LP
4.1.1.1
	\fIConnection establishment functions\fR 
.sp 9p
.RT
.PP
The connection establishment service primitives defined in
\(sc\ 2 are used to set up a signalling connection.
.PP
The main functions of the connection establishment phase are listed
below:
.RT
.LP
	\(em
	Setup of a signalling connection;
.LP
	\(em
	Establish the optimum size of NPDUs (Network Protocol Data
Unit);
.LP
	\(em
	Map network address onto signalling relations;
.LP
	\(em
	Select functions operational during data transfer phase (for
instance, layer service selection);
.LP
	\(em
	Provide means to distinguish network connections;
.LP
	\(em
	Transport user data (within the request).
.sp 1P
.LP
4.1.1.2
	\fIData transfer phase function\fR 
.sp 9p
.RT
.PP
The data transfer phase functions provide means for a two\(hyway
simultaneous transport of messages between the two endpoints of the signalling 
connection. 
.PP
The main functions of the data transfer phase as listed below are used 
or not used in accordance with the result of the selection performed in 
the 
connection establishment phase.
.RT
.LP
	\(em
	Segmenting/reassembling,
.LP
	\(em
	Flow control,
.LP
	\(em
	Connection identification,
.LP
	\(em
	NSDU delimiting (M\(hyBit),
.LP
	\(em
	Expedited data,
.LP
	\(em
	Missequence detection,
.LP
	\(em
	Reset,
.LP
	\(em
	Receipt confirmation
.FS
The need for this functions is for
further study.
.FE
,
.LP
	\(em
	Others.
.LP
.sp 1
.bp
.sp 1P
.LP
4.1.1.3
	\fIRelease phase functions\fR 
.sp 9p
.RT
.PP
These functions provide disconnection of the signalling connection, regardless 
of the current phase of the connection. The release may be 
performed by an upper layer stimulus or by maintenance of the SCCP itself. 
The release can start at each end of the connection (symmetrical procedure). 
.PP
The main function of the release phase is the disconnection.
.RT
.sp 2P
.LP
4.1.2
	\fIFunctions for permanent signalling connections\fR 
.sp 1P
.RT
.sp 1P
.LP
4.1.2.1
	\fIConnection establishment phase and connection release\fR 
\fIphase functions\fR 
.sp 9p
.RT
.PP
The setup and release for permanent signalling connections are for further 
study. The stimuli for setup and release of permanent connections are originated 
from the Administration function. 
.RT
.sp 1P
.LP
4.1.2.2
	\fIData transfer phase functions\fR 
.sp 9p
.RT
.PP
The functions for the data transfer on permanent signalling
connections correspond to that for temporary connections. Differences may 
exist regarding the quality of service. This matter is for further study. 
.RT
.sp 1P
.LP
4.2
	\fIConnectionless service functions\fR 
.sp 9p
.RT
.PP
The functions of the connectionless service are listed
below:
.RT
.LP
	\(em
	mapping the network address to signalling relations,
.LP
	\(em
	sequence service classification.
.sp 1P
.LP
4.3
	\fIManagement functions\fR  | (for further study)\fR 
.sp 9p
.RT
.PP
The SCCP provides functions which manage the status of the SCCP
subsystems. These functions allow other nodes in the network to be informed 
of the change in status of SCCP subsystems at a node, and to modify SCCP 
translation data if appropriate. Subsystem congestion management is for 
further study. 
.PP
Functions are also provided to allow a coordinated change of status of 
replicated SCCP subsystems. At present, this allows a replicated subsystem 
to be withdrawn from service. 
.PP
When a subsystem is out of service, SCCP test functions are activated at 
nodes receiving unavailability information. At periodic intervals the status 
of the unavailable subsystem is checked by a SCCP management procedure. 
.PP
Broadcast functions within SCCP management broadcast subsystem status changes 
to nodes within the network which have an immediate need to be informed 
of a particular signalling point/subsystem status change. 
.PP
Notification functions to local subsystems within the node (local
broadcast) are also provided.
.RT
.sp 1P
.LP
4.4
	\fIRouting and translation functions\fR (for further study)
.sp 9p
.RT
.PP
The SCCP routing provides a powerful address translation function, which 
is asked for connectionless and connection\(hyoriented service. Detailed 
description of the SCCP routing function can be found in Recommendation\ 
Q.714, \(sc\(sc\ 2.2 and\ 2.3. 
.PP
The basic translation function performed by the SCCP is to transfer
the SCCP address parameter from a global title to a point code and a subsystem 
number. Other translation results are also possible. The global title form 
of the address could typically be dialed digits (e.g.\ a Freephone (800) 
number). Several standardized CCITT numbering plans may be supported by 
SCCP; details 
are given in Recommendation\ Q.713, \(sc\ 3.4.
.PP
The address translation capabilities of the SCCP in relation to
handling OSI Network Service Access Points (NSAP) are for further study.
.bp
.RT
.ce 1000
ANNEX\ A
.ce 0
.ce 1000
(to Recommendation Q.711)
.sp 9p
.RT
.ce 0
.ce 1000
\fBOSI network layer conformance\fR 
.sp 1P
.RT
.ce 0
.PP
The following information should be taken into account when
reading Recommendation\ Q.711 in relation to the provision of an OSI network
layer service.
.sp 1P
.RT
.PP
All references to connectionless classes 0 and 1 are not included in Recommendation\ 
X.200. 
.sp 1P
.LP
\fI\(sc 2.1.1\fR 
.sp 9p
.RT
.PP
The Connection identification parameters in the following
primitives are implicit in Recommendation\ X.213:
.RT
.LP
	N\(hyCONNECT
.LP
	N\(hyDATA
.LP
	N\(hyEXPEDITED DATA
.LP
	N\(hyDATA ACKNOWLEDGE
.LP
	N\(hyDISCONNECT
.LP
	N\(hyRESET
.PP
The N\(hyINFORM primitive does not exist within
Recommendation\ X.213.
.PP
The connection establishment interface elements described in
\(sc\ 2.1.1.3.2 is not required to support an OSI network layer
service.
.RT
.sp 1P
.LP
\fI\(sc 2.1.2\fR 
.sp 9p
.RT
.PP
Permanent connection services are not defined in
Recommendation\ X.200 and are not required to support an OSI network layer
service. The service is offered by the SCCP for specific No.\ 7
applications.
.RT
.sp 1P
.LP
\fI\(sc 2.2\fR 
.sp 9p
.RT
.PP
Connectionless network service is still under study in Study
Group\ VII and is not defined in Recommendation\ X.213.
.RT
.sp 1P
.LP
\fI\(sc 2.3\fR 
.sp 9p
.RT
.PP
This section on SCCP management is not defined in
Recommendation\ X.213 and none of the primitives exist in OSI.
.RT
.ce 1000
APPENDIX
.ce 0
.ce 1000
(to Recommendation Q.711)
.sp 9p
.RT
.ce 0
.ce 1000
\fBUnresolved issues in SCCP Recommendations\fR 
.sp 1P
.RT
.ce 0
.PP
This appendix lists the topics in SCCP on which study is
continuing in the next study period. It is not an exhaustive list, but does
indicate where the Recommendations might change. In these areas, RPOAs 
may need to supplement the Recommendations, but in such a way as not to 
conflict with 
ongoing work; implementors should consider likely future developments and,
where possible, design to accommodate these.
.sp 1P
.RT
.PP
The topics under study are listed below; the references are to the Blue Book.
.LP
	1)
	Inter\(hynodal communication model with SCCP connectionless
service (\(sc\ 1.3.3, Rec.\ Q.711);
.LP
	2)
	Delivery confirmation service (N\(hyDATA ACKNOWLEDGE primitive)
(Table 1/Q.711);
.LP
	3)
	Transitions caused by N\(hyDATA ACK primitive
(Figure\ 7/Q.711);
.bp
.LP
	4)
	Facilities causing differences in the called and responding
addresses in N\(hyCONNECT request and response
(\(sc\ 2.1.1.2.2, Rec.\ Q.711);
.LP
	5)
	The need for Receipt Confirmation Service in SCCP
(\(sc\(sc\ 2.1.1.2.2 and 4.1.1.2, Rec.\ Q.711);
.LP
	6)
	Connection identification parameter inclusion in Request
types\ 1 and\ 2, and reply primitives between SCCP and ISUP
(\(sc\ 2.1.1.3.2, Rec.\ Q.711);
.LP
	7)
	Connection identification parameter inclusion in N\(hyCONNECT,
N\(hyDATA, N\(hyEXPEDITED DATA, N\(hyRESET, and N\(hyDISCONNECT primitives
(Tables\ 2/Q.711, 3/Q.711, 4/Q.711, 5/Q.711, 6/Q.711, 7/Q.711,
8/Q.711);
.LP
	8)
	The list of release reason parameter values
(\(sc\ 2.1.1.2, Rec.\ Q.711);
.LP
	9)
	QOS parameter set inclusion in N\(hyINFORM
(Table 7/Q.711);
.LP
	10)
	Setup and release functions for permanent signalling
connections (\(sc\ 2.1.2.1, Rec.\ Q.711);
.LP
	11)
	Integrating sequence control and return option parameters
in the QOS set (Table\ 9/Q.711);
.LP
	12)
	Sequence control parameter inclusion in the N\(hyUNITDATA
indication primitive (Table\ 10/Q.711);
.LP
	13)
	SCCP response to MTP\(hySTATUS (\(sc\ 3.2.4, Rec.\ Q.711);
.LP
	14)
	Difference in QOS between permanent and temporary
signalling connections (\(sc\ 4.1.2.2, Rec.\ Q.711);
.LP
	15)
	SCCP management procedures for subsystem congestion
(\(sc\ 4.3, Rec.\ Q.711; \(sc\(sc\ 3.11, 3.12, 3.15, Rec.\ Q.713; \(sc\(sc\ 
5.1, 
5.3, Rec.\ Q.714);
.LP
	16)
	SCCP capabilities in OSI NSAP address translation
(\(sc\ 4.4, Rec.\ Q.711);
.LP
	17)
	Possible need for diagnostic parameter (\(sc\ 2.6,
Rec.\ Q.712);
.LP
	18)
	Constraints on order of optional parameter transmission
(\(sc\ 1.8, Rec.\ Q.713);
.LP
	19)
	Destination local reference coded as all ones
(\(sc\ 3.2, Rec.\ Q.713);
.LP
	20)
	Source local reference coded as all ones
(\(sc\ 3.3, Rec.\ Q.713);
.LP
	21)
	Alignment with X.96 call progress information (\(sc\(sc\ 3.11,
3.15, Rec.\ Q.713);
.LP
	22)
	Inclusion of routing failure causes as for return cause
in Recommendation\ Q.713, \(sc\ 3.12 (\(sc\ 3.15, Rec.\ Q.713);
.LP
	23)
	Data parameter maximum length for \fIUnitdata\fR  | nd
\fIUnitdata Service\fR  | messages (\(sc\(sc\ 4.10, 4.11, Rec.\ Q.713;
\(sc\(sc\ 1.1.2, 4, Rec.\ Q.714);
.LP
	24)
	Need for \fIReleased message\fR  | cause value 1110 \*Qnot
obtainable\*U (Annex\ A, Rec.\ Q.713);
.LP
	25)
	Need for \fIReset Request\fR  | message cause value 1011 \*Qnot
obtainable\*U (Annex\ A, Rec.\ Q.713);
.LP
	26)
	Notification regarding unrecognized messages/parameters
(\(sc\ 1.14, Rec.\ Q.714);
.LP
	27)
	Classification of SCCP routing failure causes
(\(sc\ 2.4, Rec.\ Q.714);
.LP
	28)
	Management procedures for non\(hydominant mode
nodes/subsystems with more than one backup
(\(sc\ 5.1, Rec.\ Q.714);
.LP
	29)
	Receipt from a local originating subsystem of a message
for a prohibited subsystem (\(sc\ 5.3.2.1, Rec.\ Q.714);
.LP
	30)
	Possible introduction of a subsystem out of service denial
message (\(sc\ 5.3.5.3, Rec.\ Q.711);
.LP
	31)
	Mathematical analysis of SCCP performance;
.LP
	32)
	Recommendation\ Q.716 parameter valus (\(sc\ 3,
Rec.\ Q.716).
.LP
.bp