(Based on Question 19/13 studied during 1997-2000)

Background and justification

There is a need to study core network architectures and interworking principles and features for IP-based and other networks in order to enhance existing Recommendations and to develop new Recommendations. This work will take into account new technologies (e.g. variable size packets, high-speed transport networks) to provide high throughput and low delay transport capabilities. Restoration methods, multi-layer survivability and principles for interworking in terms of exchanged characteristic information between different transport and layer networks also need to be studied. Further enhancements are needed to the requirements for the management capabilities of transport networks. Also the technology independent requirements for new transport networks need to be studied.

This work is complementary to the activities in ITU-T SG 15 on technology specific transport network architecture aspects.

Items for study

1) Development of a new Recommendation (G.cls) to define the transport network architecture for connectionless layer networks.

2) The relationship between transport network architectural models and other models, e.g. Open System Interconnection (OSI), Advanced Intelligent Network (AIN) and Global Information Infrastructure (GII).

3) Rerouting based restoration methods, principles for multi-layer survivability and interactions of protection/restoration between transport layer networks, including IP layer networks. Definition and description of generic protection schemes in the new Recommendation G.gps.

4) The principles of interworking between transport and layer networks including high-speed variable size packet data networking (e.g. IP over OTN).

Tasks with deadlines

Development of new Recommendations (G.cls and G.gps) by 2002;

Other relevant Recommendations to be determined.

Relationships

• ITU-T study groups on AIN
• ITU-T study groups on TMN and network maintenance
• ITU-T study groups on transport systems and equipment
• ITU-R study groups on mobile, radio and satellite systems
• IETF