The IESG has approved the following document: - 'Structure-aware TDM Circuit Emulation Service over Packet Switched Network (CESoPSN) ' <draft-ietf-pwe3-cesopsn-07.txt> as an Informational RFC This document is the product of the Pseudowire Emulation Edge to Edge Working Group. The IESG contact persons are Mark Townsley and Jari Arkko. A URL of this Internet-Draft is: http://www.ietf.org/internet-drafts/draft-ietf-pwe3-cesopsn-07.txt Technical Summary This draft extends the work described in RFC4553 by describing one method of encapsulating structured (NxDS0) Time Division Multiplexed (TDM) signals as pseudo-wires over packet-switching networks (PSN). The use of a structure aware method of emulating NxDS0 circuits provides for saving PSN bandwidth, supports DS0-level grooming and distributed cross-connect applications. It also enhances resilience of CE devices to effects of loss of packets in the PSN. The structured method described in this draft uses a structure locking mechanism in which there is a constant relationship between a particular DS0 circuit and the position in which the corresponding information is carried in the PW payload. The method provides the ability to keep the edge-to-edge delay of the emulated service independent of the service rate. Working Group Summary Although the Working Group was able to reach consensus on the unstructured TDM emulation method (SAToP/RFC4553), it could not reach consensus on the best method of emulating a structured service. The PWE3 WG therefore decided to pursue two methods as informational RFCs(draft-ietf-pwe3-cesopsn-07.txt and draft-ietf-pwe3-tdmoip-05.txt) and to gain operational experience with the technology before recommending a standards track approach. Protocol Quality There are many implementations of this protocol, and it is in operational service. Note to RFC Editor Section 4.4 OLD TEXT 4.4. Usage of the RTP header When a fixed RTP header (see [RFC3550], Section 5.1) is used with CESoPSN, its fields are used in the following way: NEW TEXT 4.4. Usage of the RTP header Although CESoPSN MAY employ an RTP header when explicit transfer of timing information is required, this is purely formal reuse of the header format. RTP mechanisms, such as header extensions, CSRC, list, padding, RTCP, RTP header compression, SRTP, etc. are not applicable to CESoPSN pseudowires. When a fixed RTP header (see [RFC3550], Section 5.1) is used with CESoPSN, its fields are used in the following way: END Section 9 (Security Considerations) OLD TEXT Although CESoPSN PWs MAY employ an RTP header when explicit transfer of timing information is required, SRTP (see [RFC3711]) mechanisms are NOT RECOMMENDED as a substitute for PW layer security. NEW TEXT Although CESoPSN MAY employ an RTP header when explicit transfer of timing information is required, it is not possible to use SRTP (see [RFC3711]) mechanisms as a substitute for PW layer security. END _______________________________________________ IETF-Announce@ietf.org https://www1.ietf.org/mailman/listinfo/ietf-announce
