Status Report on IP/Telecommunications Interworking

Transcription

1 GSC#5/RAST#8 Williamsburg, Virginia, USA August 1999 GSC5 (99) 32 SOURCE: TITLE: Committee T1 Status Report on IP/Telecommunications Interworking AGENDA ITEM: 10.6 DOCUMENT FOR: Decision Discussion Information X 1 DECISION/ACTION REQUESTED None. The following summarizes the IP-related work activities in Committee T1 s Technical Subcommittees (TSCs). The information includes completed work, work in progress, and work that is planned. 2 REFERENCES N/A 3 RATIONALE Committee T1 Activities on IP/Telecommunications Interworking IP/Telecommunications Interworking issues have been worked in four of Committee T1 s Technical Subcommittees: T1A1, T1M1, T1S1, and T1X1. A summary of the work completed, in progress, and planned is presented for each TSC. T1A1 (Performance and Signal Processing) T1A1 has initiated a number of projects aimed at developing performance and signal processing standards and technical reports addressing public Internet services. Their motivation was that the explosive growth of public Internet services has raised questions of fundamental importance to T1A1 standardization efforts. Performance measures for endto-end Internet services have not been standardized, nationally or internationally. Delay, information loss, and other performance aspects of current, "best effort" Internet-based services are of increasing concern to users. At the same time, new Internet-based services are promising radically different capabilities (e.g., multimedia, streaming) that will require assured performance levels. Coding standards are required for IP-based telephony. Also, there are concerns regarding the interworking of Internet services with the PSTN and advanced public network capabilities such as ISDN and B-ISDN.

2 T1 Technical Report 55, Reliability and Survivability Aspects of the Interactions Between the Internet and the Public Telecommunications Network. This Technical Report addresses the reliability and survivability aspects of the interactions between the Internet and the Public Telecommunications Network (PTN). It examines the general architectures of both networks and the interfaces between them. This document offers suggestions for meeting reliability challenges posed by changing network traffic characteristics. Two major categories of solutions are introduced: network engineering and network architecture. Within these categories, alternatives may be selected depending on the operator's local circumstances. T1 Technical Report 56, Performance Guidelines for Voiceband Services over Hybrid Internet/PSTN Connections. This Technical Report provides transmission performance guidelines for voiceband services over networks that are an interconnection of an IP network (e.g., "the Internet") and the PSTN. As modern telecommunications systems continue to evolve, hybrid networks of various kinds will become more prevalent. This tendency, together with the reality that voiceband communications will be an important source of traffic on such networks, has led T1A1 to develop this Technical Report. The intent is to provide to a wide audience a set of principles on transmission performance aspects of hybrid Internet/PSTN connections. An American National Standard ("T1.5IP") that will define performance parameters to characterize end-to-end public data communication services using the Internet Protocol (IP). T1.5IP is structured as a delta document, with the approved text of ITU-T Recommendation I.380 as its base. Presuming that the final text of I.380 (after the February SG 13 meeting at which it is to be decided ) is not objectionable, the T1A1 chair will be authorizing a letter ballot of T1.5IP before the May T1A1 meeting. An American National Standard ("T1.8Internet") that will define Internet Reference Connections for transporting multimedia services. An American National Standard that will define Quality of Service (QoS) for business multimedia communications. Parameters defined to date are being related to IP packet transfer parameters defined in ITU-T Recommendation I.380 and to a set of multimedia QoS parameters defined by the Multimedia Communications Forum. A T1 Technical Report to address end-to-end aspects of Internet service survivability. A Supplement to T1.8Internet to define associated service performance parameters and measurement methods at the connection interface points. A Supplement to T1.8Internet to define corresponding performance specifications for various service categories. The initial emphasis of the work will be on video teleconferencing and video telephony applications. A study of voice and voiceband data performance issues of transport over non-pstn networks, including IP-based networks, that may be interconnected with the PSTN. Two new T1 Technical Reports will result from this work. The first will consider performance and the second will define statistical tools for measuring end-to-end performance

3 T1M1 (Internetwork Operations, Administration, Maintenance, and Provisioning) None At their November 13 meeting, the chair of T1M1 provided information exchanged with IETF members regarding the formation of a new group to define access gateway controller and protocol between the controller and gateway. The charter of the group did not indicate how management of the gateway would be specified. A liaison was sent explaining the management activities in T1M1 and requesting coordination between the various IP/TMN integration activities in ITU and IETF. T1M1 should jointly work with the IETF, ITU-T, and others on the management, performance, and interoperability for next generation networks, including packet and cell technologies, for voice, data, image, and video. INPUT required: Next generation network architectures need to be defined by some committee, such as T1, IETF, ITU-T and/or others, in parallel with T1M1 contributing to the definition of management thereof. Examples of work product from T1M1 along with the IETF and others might include specific management aspects of layer 2 relating to packet and cell transport. Any common language designations relating to packet and cell technologies need to be developed by T1M1. T1M1 should work with others to define how we intend to integrate the management of current networks along with these future networks. ITU-T SG 4 s intentions are described in Annex 3 to TSB Collective Letter 6/4 (see Annex B of this document). T1M1 will work with other bodies on an open basis, building upon our current standards, but not limiting our choices for the future. T1M1 recognizes the recent internal organization efforts of the OIF that recently formed a working group to address OAM&P and a working group for physical & link layer. T1 operating procedures may impede us working with the IETF. As an example of flexibility, perhaps the manner in which we worked with TIA may work for this project. It was suggested that Committee T1 consider formalizing cross-referencing standards with ITU-T and others as described in ITU-T Recommendation A.5 and A.6. T1S1 (Services, Architecture, and Signaling) None Various IETF Working Groups are involved in activities related to protocol interworking (e.g., SS7/H.323) and public network interworking. T1S1 provides uniqueness/expertise to deal with specific problems/issues such as the signaling/service application to public networks, - 3 -

4 interconnectivity of networks, operational aspects of public networks (in contrast to private networks), and experience in dealing with FCC matters. T1S1 expects to draw on its experience with existing networks and technology to interwork and integrate new technologies. There are potential hazards of the IETF not working with T1S1 (.e.g., incompatibilities between North American and ITU SS7, time potentially wasted in reinventing network procedures for signaling and services). T1S1 currently provides: Support for the IETF PINT Work in ITU-T SG11 Support for the implementation of SS7 over IP in ITU-T SG11 Review and support for architecture under development on ETSI TIPHON activity via ITU-T SG11 The ITU-T SG11 activity is driven by the following five activities which are currently being supported in T1S1: 1. Efficiently identifying and routing traffic destined for Internet Service Providers (ISPs) to minimize negative impact upon the Public Switched Telephone Network (PSTN), which has been engineered for relatively short holding time calls; 2. Defining signalling support for new, value added services which may enable public network operators, as well as ISPs, to capitalize on the growing demand for Internet based and Intelligent Network (IN) based capabilities; 3. Serving the need of ISPs, Internet Access Providers, and Internet users to flexibly manage dynamic bandwidth and quality of service demands from a public network; 4. Defining mobile wireless access to services over the Internet (e.g., virtual private networks), provided by either the ISPs or public network operators; and 5. Signalling support for Service Interworking of both dial-up Internet access data applications and Voice-over-IP applications with traditional telecommunication services, including support of signalling applications and user parts over IP based networks. Continuation of the efforts identified above in both the T1S1.3 and the new T1S1.7 Working Groups. The T1S1.3 (Common Channel Signaling) Work Group is specifically tasked with activities related to protocol interworking (e.g., SS7/H.323) and public network interworking, signalling/service application to public networks, interconnectivity of networks, and operational aspects of public networks. The new Working Group, T1S1.7 - Services, Architecture, and Control, was formed at the December 1998 T1S1 meeting. The Services, Architecture, and Control WG advances the interoperability of telecommunication systems and services through the development of service and application descriptions and their supporting protocols related to network architectures for, access signaling for, and application of circuit mode, frame mode, packet mode, and cell mode networks via existing and emerging transport (e.g. IP) technology to enable multimedia services. Specifically, the scope of the WG identifies the development and implementation of a T1 standards management program for Signaling Support of Services Over the Internet

5 T1X1 (Digital Hierarchy and Synchronization) There was some work and an active liaison in 1998 on PPP over SONET and a concern over the likelihood that the PPP scramble could cause the SONET system to fail. This work is completed