Subject: Protocol Action: PPP over AAL2 to Proposed Standard

From: The IESG <[email-masked]>
Date: Fri, 03 May 2002 15:54:13 -0400

The IESG has approved publication of the following Internet-Drafts
as Proposed Standards:

 o PPP over AAL2
       <draft-ietf-pppext-ppp-over-aal2-03.txt> 
 o Class Extensions for PPP over AAL2
       <draft-ietf-pppext-ppp-over-aal2-class-02.txt>

These documents are the product of the Point-to-Point Protocol Extensions
Working Group. The IESG contact persons are Erik Nordmark and Thomas Narten.

Technical Summary
 
PPP over AAL5 (RFC 2364) describes the encapsulation format and
operation of PPP when used with the ATM AAL5 adaptation layer. While
this encapsulation format is well suited to PPP transport of IP, it is
bandwidth inefficient when used for transporting small payloads such
as voice. PPP over AAL5 is especially bandwidth inefficient when used
with RTP header compression (RFC 2508).

'PPP over AAL2' (draft-ietf-pppext-ppp-over-aal2-02.txt) addresses the
bandwidth efficiency issues of 'PPP over AAL5' for small packet
transport by making use of the AAL2 Common Part Sublayer (CPS) to
allow multiple PPP payloads to be multiplexed into a set of ATM cells.

In addition to bandwidth efficiency, real-time applications such as
voice require low latency. RFC 2689, "Providing Integrated Services
over Low-bitrate Links", describes an architecture for providing
transport services for real time applications on low bit rate
links. The main components of the architecture are: a real-time
encapsulation format for asynchronous and synchronous low-bitrate
links, a header compression architecture optimized for real-time
flows, elements of negotiation protocols used between routers (or
between hosts and routers), and announcement protocols used by
applications to allow this negotiation to take place.

'Class Extensions for PPP over AAL2'
(draft-ietf-pppext-ppp-over-aal2-class-01.txt) defines extensions to
'PPP over AAL2' that can be used to implement a fragment-oriented
solution for the real-time encapsulation format part of the
architecture described in RFC 2689.

Working Group Summary

There was support for these documents in the WG and no issues were
raised during Last Call.

Protocol Quality

These documents have been reviewed for the IESG by Thomas Narten.