Workshop on IP/Optical

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Chitose, Japan, 9-11 July 2002

Abstract: Session 11 - Network Performance (IP/OPTICAL)

Workshop Session
NETWORK PERFORMANCE (IP/OPTICAL)
Thursday, 11 July 2002

In conjunction with the

Workshop on IP/Optical
Convened by ITU-T at the request of Study Groups 13 and 15
Chitose, Japan, 9-11 July 2002

SESSION DESCRIPTION

This workshop session will focus on network performance and related Quality of Service (QoS) requirements for IP over Optical networks, and on how those requirements are being addressed in international standards and emerging IP/Optical network infrastructures. The session will be a panel discussion featuring experts participating in key international standards and network planning groups including ITU-T Study Groups 13, 15, 12, and 4, the IETF, and the TMForum. The panelists will each give a 20-minute presentation summarizing their perspectives (and the work of industry groups in which they participate) on a particular aspect of IP/Optical network performance. The panelists and workshop attendees will then exchange views in a question-driven discussion period. Before concluding the session, the panel will consolidate the views expressed and identify insights and action items contributing to a more coherent and better-coordinated plan for achieving IP/Optical network performance requirements. The presentations and a session summary will be made available to attendees in soft copy form.

Motivation

Many network planners believe the long-awaited convergence of IP and telephony services will be based on a two-layer network architecture, in which wavelength-switched optical "core" networks (comprised of DWDM links, OXCs, and OADMs) interconnect conventional IP router "client" networks that in turn serve IP end users – and all types of application data, including real-time voice and video signals, are transported in IP packets. Such "IP/Optical" networks will support dynamic resource reservation, multi-layer traffic engineering, automatic protection switching and path restoration, and many other advanced features. They will likely employ MPLS technologies for network management and control. IP/Optical networks are expected to reduce the costs of network deployment and operation by reducing the number of network elements (and network layers) that must be installed and managed, by providing bit rate transparency, and by automating the time-consuming process of service provisioning. Such networks are expected to promote new applications and enhance service creation by expanding network capacity and providing a common platform for technology and service integration.

IP/Optical networks should also provide substantial performance benefits. In addition to increasing available capacity, switched optical core networks should offer attached IP client networks reduced packet transfer delay and delay variation, lower packet loss and error rates, and shorter delays in path provisioning and restoral. End users of concatenated IP/Optical networks should experience all of these improvements, plus lower delays and blocking probabilities in setting up individual managed IP flows or connections. IP end users should also experience improved service availability as a result of the path protection and restoration features implemented in the optical cores. However, realizing these performance benefits in practical IP/Optical networks will not be straightforward. A new performance specification and measurement framework (and associated performance parameters and objectives) will need to be defined for switched optical networks – and reconciled with the frameworks used in characterizing conventional IP (and MPLS) router networks. Unified signaling procedures will need to be developed to relate IP end user QoS requirements and traffic specifications with routing, multiplexing, traffic engineering, wavelength assignment, and other QoS control and resource allocation mechanisms used in the IP router networks and switched optical cores. A unified network management strategy will need to be identified to allow independent IP/Optical network providers to monitor performance, detect and isolate failures, and coordinate protection, restoration, and provisioning activities.

Prospective Questions

How will the performance of IP-based multi-service networks be specified on an end-to-end basis? What numerical performance requirements will VoIP and other anticipated real-time IP applications impose? What new applications will drive the deployment of integrated IP/Optical infrastructures, and what new performance requirements will they entail? How will such requirements be allocated among IP network providers? How will IP network performance be monitored, in and out of service? How will IP network failures be localized? What mechanisms will IP-based networks implement to provide assured-quality services? How will the interactions between switched optical networks and client IP networks be modeled from a performance point of view? What kinds of parameters will be used in specifying the performance levels switched optical networks provide to their IP clients? Will standard service classes or SLAs be used to document such specifications? How will performance requirements be allocated among switched optical networks operated by different providers? How will the performance of switched optical networks be monitored? How will failures in such networks be localized? What mechanisms will be used to control resource allocation and network performance in switched optical networks? How will performance requirements (and associated traffic contracts) for IP flows supporting particular applications be communicated from IP users to the serving IP router networks? What signaling mechanisms will be used to communicate optical path performance and capacity requirements from IP clients to serving optical core networks, and among concatenated optical networks? How will IP QoS signaling be coordinated with optical network performance signaling in IP/Optical networks? How will the requirements of IP end users be reflected in optical network requirements? How will performance monitoring, failure localization, and other network management functions (e.g., protection, restoration, OAM&P) be coordinated between the IP and optical layers in IP/Optical networks? Additional questions are encouraged.^*

PANELISTS
(To be confirmed by May 17, 2002)

Al Morton, AT&T

Peter Huckett, Acterna

Tobey Trygar, Telcordia

CONTACTS

Neal Seitz - Session Chair

neal@its.bldrdoc.gov

BACKGROUND

In October of 2000, the WTSA confirmed Study Group 13 (Multi-protocol and IP-based Networks) as ITU-T Lead Study Group on IP related matters, with responsibilities including the coordination of ITU-T efforts to integrate heterogeneous telecommunication and IP-based networks and services. The WTSA also confirmed Study Group 15 as ITU-T Lead Study Group on optical technology, with responsibility for coordinating ITU-T activities involving the transport, multiplexing, routing, management, supervision, and survivability of optical channels carrying client signals. The IP/Optical Workshop will be an opportunity to further develop these roles and activities, to coordinate them with important responsibilities of other Study Groups (e.g., SGs 4 and 12) and other organizations (e.g., IETF, TMForum), and to identify key issues and strategies for the advancing the work.

OTHER WORKSHOP TOPICS IN CHITOSE

Tuesday Business and Market aspects, Switched Optical Networks.
Wednesday Optics in Access and Metropolitan Networks, Optical Interfaces, Network OAM & Protection and Restoration, WDM and DWDM, Signaling and Routing, Optical Fibers, Cables and Components, Optical Network Management.
Thursday Optical Switching and Equipment, Optical Network Clients and Services, Service and Network Evolution.

^* The discussion will not address, tariff, regulatory, or policy issues.