Reasons for the question

The desire to support existing network services and their enhancements, and the desire to introduce multimedia - multiparty network services, employing multiple bearer transport technologies, will require the specification of network-based bearer transport technology independent call control signalling protocols which support both fixed and mobile network applications.

Since both many of the existing network services and envisioned new network services can be supported by IN, it is necessary to reconcile and align the interaction between the network-based call control function and the IN functions in a bearer technology independent manner. Since every call control function may not be attached to an IN function, there is a need to provide remote call control - IN interaction support within the scope of the specification of the network based bearer transport independent call control signalling protocols.

Because of the desire of the network service providers to physically distribute network intelligence, therefore, physical separation of the functionality of network nodes is being studied in external implementation forums. Presently these forums are studying the physical separation of call control function and bearer control functions, and the physical separation of bearer control functions from switch control and port control functions. The specification of the network based bearer transport technology independent call control signalling protocols will be required to apply the concept of physical separation of call control functions and bearer transport control functions. In order that the call control functions are independent of bearer transport technology being controlled by the bearer transport control functions, the interaction between the call control functions and the bearer transport control function must be bearer technology independent.

Question

What new protocol requirements and what enhancements to existing protocol requirements are required to support the evolution of bearer transport independent signalling protocols?

Task objectives

The major focus of this question is to develop bearer transport independent call control protocol requirements to be used to support both fixed and mobile network based services. The requirement task objectives for the question are:

1) Develop a high-level functional architectural model supporting both fixed and mobile multimedia and multiparty network-based services, specifying the physical interfaces that are to be covered by this question's call control signalling requirement capability releases.

2) Develop the signalling protocol requirements for the internal network call control to call control signalling applications covered by this question's call control requirement capability releases. Information flow methodology should be used in the development of these requirements.

3) Develop the signalling protocol requirements for the call control to bearer transport control signalling protocols covered by this question's capability releases. A methodology similar to the one being used in the specification of H.248 should be considered in development of these requirements.

4) Develop the signalling protocol requirements for extension of technology-based bearer control signalling protocols that may be required in order to support bearer independent call control applications. These requirements will be released as part of this question's capability sets. Information flow methodology should be used in the development of these requirements.

5) Develop the signalling protocol requirements for network call control signalling protocols in order to support IN control of a call control function not directly attached to an IN entity. This question's capability releases will closely coincide with the IN capability releases. Information flow methodology should be used in the development of these requirements.

6) Develop the requirements for the underlying signalling transports layers needed to support the signalling protocols covered by this question. These requirements will be released as part of this question's capability sets.

7) Definition of signalling requirements to:

� Identify calls to a mobile network.

Expected Completion: 1H2001.

� Support of optimal concatenation of DME.

Expected Completion: 1H2001.

� Support ISUP/INAP interaction for INAP Capability Sets 3 and 4.

Expected Completion: 1H2001.

The outputs of this question will be recorded as ITU-T Technical Reports (supplements). These supplements will be released in phases during the study period. The phases will be called capability sets. The date for the first capability set associated with this question is presently scheduled for completion end of 2001. The contents and schedule of these capability sets will be determined though coordination with other requirement questions. The requirements of Tasks 3) and 4) may have an individual release schedules. However, their scope and schedule will closely complement the capabilities covered in the call control signalling requirement releases designated by Task 2).

Relationships

The development of these requirements will require close coordination activities with:

• Bearer control signalling protocol questions (e.g. DSS 2, B-ISUP, H.323, AAL type 2, etc.).
• Device control signalling protocol questions (e.g. H.248, etc.).
• IN service control signalling protocol questions (e.g. INAP, etc.).
• Integrated call and bearer protocol questions (e.g. DSS 1, DSS 2, ISUP, B-ISUP, H.323, etc.).
• Fixed and mobile service requirements questions and signalling protocol questions (e.g. Service Mobility Management applications, Wire line Access Network signalling (e.g. V5, VB5, etc.), Radio Access Network signalling, air interface signalling, etc.).
• Signalling transport protocol questions (e.g. MTP3, MTP3b, MTP2, SSCOP, etc.).
• External organizations (e.g. TINA, IETF, MSF, etc.).
• Other requirements questions.