Time Division Multiplexing over IP (TDMoIP)
RFC 5087

Approval announcement
Draft of message to be sent after approval:

From: The IESG <iesg-secretary@ietf.org>
To: IETF-Announce <ietf-announce@ietf.org>
Cc: Internet Architecture Board <iab@iab.org>,
    RFC Editor <rfc-editor@rfc-editor.org>, 
    pwe3 mailing list <pwe3@ietf.org>, 
    pwe3 chair <pwe3-chairs@tools.ietf.org>
Subject: Document Action: 'TDM over IP' to Informational RFC 

The IESG has approved the following document:

- 'TDM over IP '
   <draft-ietf-pwe3-tdmoip-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:

Technical Summary

This draft extends the work described in RFC4553 by describing
structure-aware methods of encapsulating Time Division Multiplexed
(TDM) signals as pseudo-wires over packet-switching networks (PSN).

The use of a structure-aware method of emulating TDM circuits make it
possible to safeguard TDM structure during transport over the PSN, thus
making possible to effectively withstand network degradations such as
packet loss events. TDM signaling also becomes visible, facilitating
mechanisms that maintain or exploit this. Finally, by taking advantage
of TDM signaling and/or voice activity detection, structure-aware TDM
transport makes bandwidth conservation possible.

Two structure-aware methods described in this draft. One uses a
structure-indication mechanism which is derived from the mechanism used
in ATM AAL1, and is best used when the channel allocation is static. The
other uses a structure-reassembly mechanism based on the mechanism used
in ATM AAL2, and may be used to conserve bandwidth when the channel
allocation is dynamic.

The methods described in this draft have been widely implemented,
and in particular are compatible with methods described in ITU-T
Recommendations Y.1413, Y.1414, Y.1452 and Y.1453.

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 a number of implementations of this protocol, and it is
in operational service. This document was reviewed by Mark Townsley.

Note to RFC Editor

Please process this draft and draft-ietf-pwe3-cesopsn (Informational)
together, resulting in close RFC numbers and completion dates if possible.


   When MPLS is the PSN, PW-specific security mechanisms will generally
   be required, while for IP-based PSNs IPsec MAY be used.  TDMoIP using
   L2TPv3 is subject to the security considerations discussed in section
   4.1.3 of [RFC3931].


   When MPLS is the PSN, PW-specific security mechanisms MAY
   be required, while for IP-based PSNs IPsec [RFC4301] MAY be used. 
   TDMoIP using L2TPv3 is subject to the security considerations
   discussed in section 8 of [RFC3931].

OLD (In TOC and Headline):

4.1  UDP/IPv4


4.1  UDP/IP

   When using L2TPv3, randomly selected cookies MAY be used to validate
   circuit origin.

	When using L2TPv3, a cryptographically random [RFC4086] Cookie
	SHOULD be used to protect against off-path packet insertion
	attacks, and a 64-bit Cookie is RECOMMENDED for protection
	against brute-force, blind, insertion attacks.

Please add informational references for [RFC4301] and [RFC4086]