ITU-T Q.81.8 PDF

This Recommendation defines the stage 2 of the Multiple Subscriber Number (MSN) supplementary service for the integrated services digital network (ISDN) as provided by telecommunications operators. Stage 2 identifies the functional capabilities and the information flows needed to support the stage 1 service description. The stage 2 description also identifies user operations not directly associated with a call (see Recommendation I.130 [1]).

This Recommendation is specified according to the methodology specified in Recommendation Q.65 [2].

This Recommendation does not formally describe the relationship between this supplementary service and the basic call, but where possible this information is included for guidance.

In addition, this Recommendation does not specify the requirements where the service is provided to the user via a private ISDN. This Recommendation does not specify the requirements for the allocation of defined functional entities within a private ISDN, it does, however, define which functional entities may be allocated to a private ISDN.

This Recommendation does not specify the additional requirements where the service is provided to the user via a telecommunications network that is not an ISDN.

The MSN supplementary service provides the possibility for assigning multiple numbers to a single public or private access.

Note – This allows e.g.:

1) a calling user to select, via the public network, one or multiple distinct terminals out of a multiple choice;

2) to identify the terminal to the network for the application of other supplementary services.

It is considered:

– that in the case of a basic access some service providers may not have knowledge or control over what is connected, e.g. a private ISDN or a terminal configuration;

– that service providers have differing numbering methods.

The MSN supplementary service is applicable to all telecommunication services.

This Recommendation is applicable to the stage 3 Recommendations for the ISDN MSN supplementary service as defined in Recommendation I.130 [1].