Question 4/XI - Switching functions and signalling information flows for
implementation of OAM functions

Considering
(a) that a Recommendation (M.30) exists on the definition of a
Telecommunications Management Network (TMN) and that exchanges and
signalling systems are a part of that network, and that Recommendation
Q.65 describes a methodology for defining information flows and
allocation of functions to signalling and switching systems;

(b) that the introduction of enhanced switching and
signalling systems provide an increasing potential for enhanced
maintenance and operations in a TMN;

(c) that the ISDN access signalling, CCITT Signalling System No. 7 and
packet switching systems will allow a greater range of information
transfer between network entities subscriber equipment and OAM centres;

(d) that OAM functions may be located in a specialized centres external
to the signalling network(s), or in signalling points within the
signalling network; and OAM functions may be centralized in specific
elements or distributed among several elements;

(e) that network architecture studies will continue in the CCITT which
could effect the studies on OAM functions and information flows, and
that there will be a need for Stage 2 studies to interact with these
architectural studies;

(f) that there is a need for OAM functions to be defined such that they
operate consistently also in a hybrid privatepublic network, virtual
private network and centrex environment and with mobile networks;

(g) that Stage 1 like descriptions of OAMTMN functions are expected to
become available;

(h) that there is a need to study the impact on exchange overload
characteristics due to common channel signalling traffic, data
information transfer between exchanges and remote operations
centressystems, etc.;

(i) that there may be a need to define managed objects
(OSI terminology),

and further considering

(j) that there is a need to ensure compatibility between:

-the information flow descriptions and the user-network signalling
systems,

-the information flow descriptions and the inter-network- entity
signalling systems,

-the user-network signalling systems and the inter-network- entity
signalling systems,

-the signalling systems and the switching and other network entities;

(k) that the CCITT has developed SDL for the unambiguous specification
and description of the behaviour of telecommunications systems;

(l) that CCITT and ISO are specifying other tools, such as abstract
syntax notation (Recommendation X.208) which may be used in Stage 2
specifications of OAM functions.

Questions
1. What enhancements to Recommendation Q.65 and what new Recommendations
are necessary to specify the Stage 2 method for:

a) describing the overall signalling information flow for OAM functions
in switching and signalling systems, and,

b) documenting the procedures for the invocation and control of the OAM
functions,

c) a method of classifying OAM functions for a systematic approach to
the definition of Stage 2 and Stage 3 descriptions?

2. What new Recommendations are necessary in applying the methodology?

a) to achieve the compatibility and consistency between operations
systems and switching and signalling systems required to implement the
OAM functions;

b) to specify the procedures within network entities and across the
user-network interface for OAM functions which require standardization
and when necessary the possible location(s) of OAM functions within the
network and at the user-network interface.

Note - This Question requires close cooperation with the present Study
Groups I, II, IV, VII, XV, and XVIII.