Question 5/XI - Application of the Stage 2 Recommendations to the
signalling protocols for services

Considering

(a) that a general Recommendation exists on a method for characterizing
services I.130, and the output of Stage 2 of the method consists of
Recommendations in the Q.70 and Q.80-Series;

(b) that signalling systems will need to evolve to support a range of
new basic and supplementary services;

(c) that there is a need to coordinate the application of Stage 2
Recommendations to the selection and definitions of protocols, and that
functions need to be allocated to both user and network entities, i.e.,
choice of specific physical scenarios from the Stage 2 Recommendations;

(d) that new supplementary services should be able to use the
appropriate component parts of Signalling System No. 7, DSS 1, andor
other CCITT protocol Recommendations;

(e) that there is a need to establish a set of generic operations and
ASEs available for use by different applications and users;

(f) that compatibility with OSI principles be considered in selecting
protocols and in devising generic operations and ASEs;

(g) that a means needs to be included for registration, cancellation and
modification of services based on input from Stage 2;

(h) that the signalling requirements for hybrid privatepublic networks,
virtual private networks, centrex and mobile networks needs to be
included;

(i) that enhancements may be necessary to both the user-network and
network signalling protocols to support the ISDN additional packet mode
services at Stage 3;

(j) that efficient interworking between the service related protocols
(e.g., DSS 1 to Signalling System No. 7) needs to be ensured;

(k) that updating of Recommendation Q.699 with regard to clarification
and correction of technical errors of existing text may be necessary;

(l) that close cooperation is needed with other CCITT Questions dealing
with:

- application of the Stage 2 Recommendation to the protocols for OAM
(Question FXI),

- OSI protocols,

- OAM protocols.

What guidance to Stage 3 signalling protocol groups, new Recommendations
andor enhancements to existing Recommendations are necessary to meet the
current and future signalling requirements of basic and supplementary
services and applications used in the evolution of ISDNs?

Study points should include:

For each service for which a Stage 3 definition is to be provided:

-selection of higher andor lower layer protocols needed to support the
service and identification of their roles and relationships;

-identification where appropriate of common elements of procedure andor
application service elements;

-identification of common encodings.