Motivation

As critical communications services increase their reliance on new networking technologies like MPLS, Ethernet over core networks, and other new aspects of the NGN, network performance remains important to the user’s experience. When several network operators work together to provide end-to-end communications, each needs to understand how to achieve the end-to-end performance objectives. Such objectives must be both adequate for the service being offered and feasible based on the available networking technologies.

A framework is needed to guide the development of Recommendations for performance aspects of new network capabilities, transmission facilities, and transport services (e.g., Forward Error Correction and Retransmission Protocols), including those supported by the emerging and heterogeneous infrastructure. Such a framework is also essential for relating performance Recommendations focused on other protocols or service layers to the networking layers.

When new networking technologies are proposed, it is not clear whether they will become sufficiently important to warrant the development of one or more new Recommendations on performance parameters, methods of measurement, and/or numerical objectives. Some investigation of each technology is worthwhile to determine whether it is an appropriate candidate.

The following major Recommendations, in force at the time of approval of this Question, fall under its responsibility:

I.350, I.351, I.353, I.355, I.356, I.357, I.381, Y.800, Y.1540, Y.1541, Y.1542, Y.1543, Y.1560, Y.1561.

Question

Study items to be considered include, but are not limited to:

• General and cross-technology performance studies
  • How should the generic measurement points, reference events, communication functions, performance outcomes, and performance parameters defined in ITU-T Recommendations be supplemented to address new network capabilities (e.g. multipoint connections, multi-connection calls, and modification of connection attributes), new access arrangements (e.g. wireless, satellites (including LEOs), HFC, xDSL), and new services/applications (e.g. interactive multimedia communications, personal and terminal mobility, flexible routing and charging, security, Internet access, and virtual private networks)?
  • How can the measurement of packet networks be improved, for example, to support more meaningful service level specifications between network operators and their customers?
  • How can the measurement of packet networks be coordinated, to address the issues and complexities associated with large network scale?
  • How should Recommendations on network performance address communications built on heterogeneous networking technologies, such as seamless wired-wireless communications support?
  • What new metrics can be developed and specified to serve the packet network infrastructure, including the needs of measurement systems and other fundamental applications (such as timing systems)?
  • How can the definition or the measurement of packet loss be improved to discriminate events that affect end systems and user applications?
  • How can the definition or the measurement of packet delay variation be improved to provide more information to end-system designers?
  • Considerations on how to help measure and mitigate climate change
• New technology network performance
  • Which layer(s) or other conventions have end-to-end significance in specifying performance the new technology?
  • What reference events will be available to define performance parameters for these networks?
  • What performance parameters and statistics should be standardized for such networks?
  • How can complex topologies be assessed, such as multipoint-to-multipoint?
  • What QoS levels will be needed by the services supported on these networks?
  • How will the end-to-end QoS objectives for new services be achieved when more than one network participates in the provision of communications?
  • To what extent will QoS commitments depend on the existence of traffic contracts that completely specify the characteristics of the offered traffic?
  • How will QoS commitments of networks be verified?
• T-MPLS network performance
  • Will T-MPLS be sufficiently important to warrant the development of one or more new Recommendations on performance parameters, methods of measurement, and/or numerical objectives?
  • Are there existing Recommendations that can be applied or adapted to this new networking technology?
• Ethernet network performance
  • What QoS levels will be needed by the services supported on Ethernet networks?
  • How will the end-to-end QoS objectives for Ethernet-based services be achieved when more than one Ethernet network participates in the provision of communications?
  • To what extent will QoS commitments depend on the existence of Ethernet traffic contracts that completely specify the characteristics of the offered Ethernet traffic?
  • How will QoS commitments of Ethernet networks be verified?
• MPLS network performance
  • How many QoS classes will be required by the services intended for MPLS networks?
  • How will the end-to-end QoS objectives for MPLS-based services be achieved when more than one MPLS network participates in the provision of communications?
  • To what extent will QoS commitments depend on the existence of MPLS (labelled or PHP) traffic contracts that completely specify the characteristics of the offered MPLS traffic?
• IP network performance
  • What additional performance objectives for systems employing application-layer packet loss compensation should be specified in Recommendation Y.1541?
  • How will the end-to-end QoS objectives for IP-based services be achieved when more than one IP network participates in the provision of communications?
  • How will users of IP-based services communicate their need for an IP QoS commitment?
  • What additional performance objectives for compressed data (e.g. MPEG video, G.72x codec signals) should be specified in Recommendation Y.1541?
• Collaborative performance studies
  • How can the transmission error and availability objectives specified for SDH be related quantitatively to performance objectives for carrier Ethernet services and to packet layer performance observed in IP networks?
• Considerations on how to help measure and mitigate climate change.
  • How should the study items areas be organized into tasks?

Tasks

Tasks include, but are not limited to:

• Draft new Recommendation on new technology performance parameters.
• Draft new Recommendation on T-MPLS performance parameters.
• Draft new Recommendation on Ethernet performance objectives.
• Draft new Recommendation on MPLS performance objectives.
• Updates and Maintenance on Y.1541 IP-based Network Objectives.
• New or Revised Recommendation on IP/Packet performance parameters.
• Additions and updates to other existing Recommendations.

An up-to-date status of work under this Question is contained in the SG 12 Work Programme http://www.itu.int/ITU-T/workprog/wp_search.aspx?isn_sp=545&isn_sg=551

Relationships

Recommendations: I.371, I.381, I.610, O.191, G.828, Y.1710, Y.1711, Y.1731.

Questions: 10/12, 13/12, 11/12

Study Groups:

ITU-T SG 2, SG 13, SG 15, SG 16, SG 17

ITU-R SG 5 and SG 6

Other bodies:

Metro Ethernet Forum on performance issues

IETF working groups on performance issues

IEEE 802 LAN/MAN Standards Committee