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\fBRecommendation\ Q.87\fR 
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\fBADDITIONAL\ INFORMATION\ TRANSFER\ SUPPLEMENTARY\ SERVICES\fR 
.EF '%	Fascicle\ VI.1\ \(em\ Rec.\ Q.87''
.OF '''Fascicle\ VI.1\ \(em\ Rec.\ Q.87	%'
.ce 0
.sp 1P
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\fB1\fR 	\fBISDN user\(hyto\(hyuser signalling services\fR 
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1.1
	\fIGeneral\fR 
.sp 9p
.RT
.PP
This Recommendation provides information on the functions in ISDN entities 
and the information flows between the entities which are required to provide 
user\(hyto\(hyuser signalling services. 
.PP
The service may be used for unrestricted user signalling information in 
a packet manner over the D\ channel at the user\(hynetwork interface. 
.RT
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1.2
	\fIDescription of service uses\fR 
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1.1.1
	\fIGeneral description\fR 
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.RT
.PP
The \fBuser\(hyto\(hyuser signalling (UUS) supplementary service\fR allows 
an ISDN user to send/receive a limited amount of information to/from another 
ISDN user over the signalling channel in association with a call to the 
other ISDN user. 
.PP
\fINote\fR \ \(em\ These procedures are applicable to user\(hyto\(hyuser 
information (UUI) transfer in association with a circuit\(hyswitched telecommunication 
service only. Procedures to permit UUI transfer in association with other 
types of 
calls (e.g.\ packet bearer services) need to be investigated.
.RT
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1.2.2
	\fISignalling information transfer\fR 
.sp 9p
.RT
.PP
This packet service allows two users (e.g., terminals, PABXs) in a point\(hyto\(hypoint 
configuration, to communicate via the ISDN over the D\ channel. 
.PP
Service 1 provides this capability within the basic call signalling
messages. Services\ 2 and\ 3 allow this capability within additional messages.
Service\ 2 may be sent from SETUP through SETUP confirmation (CONNECT) and
Service\ 3 from SETUP confirmation through DISCONNECT.
.RT
.sp 1P
.LP
1.2.3
	\fIService invocation\fR 
.sp 9p
.RT
.PP
Users indicate their intended user of a user\(hyto\(hyuser signalling
service at the time of call setup by including appropriate information 
in the service request sent to the network over the user/network signalling 
channel 
(D\ channel) or for Service\ 1 by including user\(hyto\(hyuser information 
in the 
SETUP message. If the request is an explicit request at call setup, the user
may mark the request essential/not essential. If the request is essential 
the call will be cleared by the network if any essential user\(hyto\(hyuser 
service 
cannot be provided. Service\ 3 may be activated by either the calling or 
called user during the setup or active phase of the call. 
.RT
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1.3
	\fIDerivation of the functional model for user\(hyto\(hyuser signalling\fR 
.sp 1P
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1.3.1
	\fIFunctional model\fR 
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.rs
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\fBFigure 1\(hy1/Q.87, p.\fR 
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.bp
.PP
FE1 and FE5 are the functional entities that serve the users and are responsible 
for initiating functional requests and interacting with 
network:\ FE2, 3 and\ 4 are the functional entities within the network that
cooperate with their peers to provide the services requestedby\ FE1 and\ /FE5.
r\d1\uand\ r\d2\uare relationships between functional entities wherein
information flows occur in order to process call attempts or service requests.
.sp 1P
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1.3.1.1
	\fIRelationship to basic service\fR 
.sp 9p
.RT
.PP
Service 1 is carried across the network as part of Basic Service. Services\ 
2 and\ 3 allow additional messages to be accepted and processed from 
specific states in the basic service model. These messages do not alter the
state but require an action to take place.
.RT
.sp 1P
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1.3.1.2
	\fIDescription of the call control Agent functional entity\fR 
.sp 9p
.RT
.PP
The CCA functional entity supports the functionality to:
.RT
.LP
	a)
	access the service\(hyproviding capabilities of the CC
entities, using service requests to establish, manipulate and release a 
single call; 
.LP
	b)
	 receive indications relating to the call from the CC entity and relay 
them to the user; 
.LP
	c)
	maintain call state information as perceived from this
functional end\(hypoint of the service (i.e., a single\(hyended view of the
call).
.sp 1P
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1.3.1.3
	\fIDescription of the call control (CC) functional entity\fR 
.sp 9p
.RT
.PP
The CC functional entity supports the functionality to:
.RT
.LP
	a)
	establish, manipulate and release a single call (upon
request of the CCA entity);
.LP
	b)
	 associate and relate the CCA entities that are involved in a particular 
call and/or service; 
.LP
	c)
	 manage the relationship between the CCA entities involved in a call (i.e., 
reconcile and maintain the overall perspective of the call and/or service); 
.sp 1P
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1.4
	\fIInformation flow diagrams\fR 
.sp 9p
.RT
.PP
Information flow diagrams for user\(hyto\(hyuser signalling service call 
setup, service usage and call release are shown in Figures 1\(hy2/Q.87 
to 
1\(hy10/Q.87.
.RT
.LP
	\(em
	 Figure 1\(hy2/Q.87 shows a successful use of UUS Service 1 in a point\(hyto\(hy 
point configuration; 
.LP
	\(em
	 Figure 1\(hy3/Q.87 shows a successful use of UUS Service 1 in a point\(hyto\(hy 
multipoint configuration; 
.LP
	\(em
	 Figure 1\(hy4/Q.87 shows a successful use of UUS Service 2 in a point\(hyto\(hy 
point configuration; 
.LP
	\(em
	Figure 1\(hy5/Q.87 shows an unsuccessful use of UUS Service 2
in a point\(hy to\(hymultipoint configuration;
.LP
	\(em
	Figure 1\(hy6/Q.87 shows a successful use of UUS Service 3
requested and essential;
.LP
	\(em
	Figure 1\(hy7/Q.87 shows a successful use of UUS Service 3
requested and not essential;
.LP
	\(em
	Figure 1\(hy8/Q.87 shows a successful use of UUS Service 3
requested during the active phase;
.LP
	\(em
	Figure 1\(hy9/Q.87 shows a successful use of UUS Service 3
requested during the active phase by the called party;
.LP
	\(em
	Figure 1\(hy10/Q.87 shows a UUS service requested in a
point\(hyto\(hymultipoint configuration.
.LP
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Blanc
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\fBFigure 1\(hy2/Q.87, p. 2\fR 
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\fBFigure 1\(hy3/Q.87, p. 3\fR 
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\fBFigure 1\(hy4/Q.87, p. 4\fR 
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\fBFigure 1\(hy5/Q.87, p. 5\fR 
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\fBFigure 1\(hy6/Q.87, p. 6\fR 
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\fBFigure 1\(hy7/Q.87, p. 7\fR 
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\fBFigure 1\(hy8/Q.87, p. 8\fR 
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\fBFigure 1\(hy9/Q.87, p. 9\fR 
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.sp 47P
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\fBFigure 1\(hy10/Q.87, p. 10\fR 
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1.5
	\fISLD diagrams for functional entities\fR 
.sp 1P
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1.5.1
	\fISLDs for FE1 and FE5\fR 
.sp 9p
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.LP
.rs
.sp 50P
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\fBFigures 1\(hy11 et 1\(hy12/Q.87, p. 11 et 12\fR 
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\fBFigure 1\(hy13/Q.87, p. 13\fR 
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\fBFigure 1\(hy14/Q.87, p. 14\fR 
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\fBFigure 1\(hy15/Q.87, p. 15\fR 
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\fBFigure 1\(hy16/Q.87, p. 16\fR 
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1.5.2
	\fIStage 2 SDLs for FE2 \*QCC functional entity (r\fI
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\fBFigure 1\(hy17/Q.87, p. 17\fR 
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\fBFigure 1\(hy18/Q.87, p. 18\fR 
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\fBFigure 1\(hy19/Q.87, p. 19\fR 
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\fBFigure 1\(hy20/Q.87, p. 20\fR 
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\fBFigure 1\(hy21/Q.87, p. 21\fR 
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\fBFigure 1\(hy22/Q.87 (feuillet 1 sur 2), p. 22\fR 
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\fBFigure 1\(hy22/Q.87 (feuillet 2 sur 2), p. 23\fR 
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\fBFigure 1\(hy23/Q.87, p. 24\fR 
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\fBFigure 1\(hy24/Q.87, p. 25\fR 
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\fBFigure 1\(hy25/Q.87, p. 26\fR 
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\fBFigure 1\(hy26/Q.87, p. 27\fR 
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1.5.3
	\fISLDs for functional entity FE3\fR 
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\fBFigure 1\(hy27/Q.87, p. 28\fR 
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1.5.4
	\fISDL for functional entity FE4\fR 
.sp 9p
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\fBFigure 1\(hy28/Q.87, p. 29\fR 
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\fBFigure 1\(hy29/Q.87, p. 30\fR 
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\fBFigure 1\(hy30/Q.87, p. 31\fR 
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1.6
	\fIFunctional entity actions\fR 
.sp 1P
.RT
.sp 1P
.LP
1.6.1
	\fICheck UUS service request\fR \v'3p'
.sp 9p
.RT
.LP
	\(em
	Check for implicit Service 1 request
.LP
	\(em
	Check for explicit service requests
.LP
	\(em
	Determine any services are essential
.LP
	\(em
	Are services subscribed to?
.LP
	\(em
	Are there sufficient signalling resources?
.sp 1P
.LP
1.6.2
	\fICheck for UUI to END user\fR \v'3p'
.sp 9p
.RT
.LP
	\(em
	UUI requested?
.LP
	\(em
	Any UUI required?
.LP
	\(em
	Is the user an ISDN user?
.bp
.sp 1P
.LP
1.6.3
	\fICheck called user response\fR \v'3p'
.sp 9p
.RT
.LP
	\(em
	Is user multipoint?
.LP
	\(em
	Can user accept UUI Service 2?
.LP
	\(em
	Are all required services accepted?
.sp 1P
.LP
1.6.4
	\fICheck which services are available to calling user\fR \v'3p'
.sp 9p
.RT
.LP
	\(em
	Which services were requested?
.LP
	\(em
	Which services were confirmed by called user?
.LP
	\(em
	Inform calling user of accepted services
.sp 1P
.LP
1.6.5
	\fIIs UUI or UUM transfer allowed?\fR \v'3p'
.sp 9p
.RT
.LP
	\(em
	Is there UUI or UUM?
.LP
	\(em
	Is the appropriate service active?
.LP
	\(em
	If UUM is the network congested?
.sp 1P
.LP
1.6.6
	\fICheck limit of Service 2 UUMs\fR \v'3p'
.sp 9p
.RT
.LP
	\(em
	Count UUMs
.LP
	\(em
	Reject UUMs over 2 coming from attached user
.sp 1P
.LP
1.6.7
	\fICan a UUI compatible path be found?\fR \v'3p'
.sp 9p
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.LP
	\(em
	Is UUS required?
.LP
	\(em
	If there is no compatible path act appropriately
.sp 1P
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1.7
	\fIAllocation of functional entities to physical location\fR 
.sp 9p
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.PP
The mapping between functional entities of the functional model for the 
user signalling bearer service and their possible physical locations is 
given in the matrix shown in Table\ 1\(hy1/Q.87.
.RT
.ce
\fBH.T. [T1.87]\fR 
.ce
TABLE\ 1\(hy1/Q.87
.ce
\fBPossible physical location of functional entities\fR 
.ps 9
.vs 11
.nr VS 11
.nr PS 9
.TS
center box;
cw(90p) | cw(24p) | cw(18p) | cw(24p) | cw(18p) | lw(24p) .
FE1	FE2	FE3	FE4	FE5	
_
.T&
lw(90p) | cw(24p) | cw(18p) | cw(24p) | cw(18p) | lw(24p) .
TE (User terminal equipment)	X				
.T&
lw(90p) | cw(24p) | cw(18p) | cw(24p) | cw(18p) | lw(24p) .
NT2 (Network termination 2)	X	X			
.T&
lw(90p) | cw(24p) | cw(18p) | cw(24p) | cw(18p) | lw(24p) .
LE (Local exchange)	X	X	X 		
.T&
lw(90p) | cw(24p) | cw(18p) | cw(24p) | cw(18p) | lw(24p) .
TR (Transit exchange)			X 		
.T&
lw(90p) | cw(24p) | cw(18p) | cw(24p) | cw(18p) | cw(24p) .
LE (Local exchange)			X	X	X
.T&
lw(90p) | cw(24p) | cw(18p) | cw(24p) | cw(18p) | cw(24p) .
NT2 (Network termination 2)				X 	X
.T&
lw(90p) | cw(24p) | cw(18p) | cw(24p) | cw(18p) | cw(24p) .
TE (User terminal equipment)					X
.TE
.LP
\fINote\fR
\ \(em\ A cross in the matrix indicates a possible allocation of the
functional entity on top of the column to the physical location on each
line. Different call scenarios can be generated from this matrix.
.nr PS 9
.RT
.ad r
\fBTable 1\(hy1/Q.87 [T1.87], p.\fR 
.sp 1P
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.ad b
.RT
.sp 2P
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\fB2\fR 	\fBUser signalling bearer services\fR 
.sp 1P
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.PP
Under study.
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