Question 8/XI - Structure and use of Signalling System No. 7 networks

Considering

(a) that the use of signalling networks employing non-associated
signalling should provide significant operational and economic
advantages to
Signalling System No. 7;

(b) that such a signalling network should be designed to support and
serve as a transport system for many, as yet undefined, services for
call control signalling and for the transmission of other non-call
related information;
(c) that guidelines for the structure of such a network should aid the
inter-connection of Signalling System No. 7 networks and simplify
signalling network management taking into account the existence of
multiple RPOAs in a country and their need for diversity of services;

(d) that the need to identify performance, reliability and security
requirements of the Signalling System No. 7 network, to consider the
parameters of the functional entities defined and quantified in the
appropriate Sub-Working Parties and incorporate them into all Signalling
System No. 7 network applications and to define guidelines on the
responsibilities of network components which together support the
required performance;

(e) that the need to establish standard methods for description and
analysis or common channel signalling network models, e.g., for the
deployment of software tools;

(f) that the need to establish one or more realistic reference
signalling network models - realistic in the sense of size and structure
- in order to prove the completeness and the proper working of
procedures and algorithms and to investigate the dynamic influence of
these procedures and algorithms on the signalling networks;

(g) that during the evolution of the signalling system different
versions of each part will be developed and general rules will be
required to ensure compatibility of each stage;

(h) that general flow control rules will be needed to ensure the
coordination of the actions of component parts of Signalling System No.
7 to maintain orderly operation under congestion and failure conditions;

(i) that the need to collate the signalling requirements for operation,
administration management networks (e.g., TMN) and to match these to an
appropriate signalling network structure,

What technical Recommendation should be produced for the structure and
use of Signalling System No. 7?

ANNEX 1

(to Question 8/XI)

Parameters for the hypothetical signalling connection

The following parameters were discussed with regard to their inclusion
in the hypothetical signalling reference connection and it was agreed
that they should be considered as a basis for study (Ref. considerata
(d)).

Proposed general parameter set for signalling network performance

Parameter

Signalling connection establishment delay (ms); Signalling connection
failure probability; Throughput; Data message (UDT or DT) transit delay
(ms); Data message delivery failure probability; Data message error
probability; Reset delay (ms); Reset failure probability; Signalling
connection unsolicited reset and premature release prob; Signalling
connection release delay (ms); Signalling connection release failure
probability; Signalling node unavailability.

In considering (d) "all Signalling System No. 7 network applications"
are mentioned. This refers to the need to include in the next study
period the hypothetical signalling reference connection for applications
such as database interrogation, public land mobile networks and other
data networks.