PPP Over Asynchronous Transfer Mode Adaptation Layer 2 (AAL2) (RFC3336)
Original Publication Date: 2002-Dec-01
Included in the Prior Art Database: 2002-Dec-13
Internet Society Requests For Comment (RFCs)
B. Thompson: AUTHOR [+3]
The Point-to-Point Protocol (PPP) provides a standard method for transporting multi-protocol datagrams over point-to-point links.
Network Working Group B. Thompson
Request for Comments: 3336 T. Koren
Category: Standards Track Cisco Systems
PPP Over Asynchronous Transfer Mode Adaptation Layer 2 (AAL2)
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright (C) The Internet Society (2002). All Rights Reserved.
The Point-to-Point Protocol (PPP) provides a standard method for
transporting multi-protocol datagrams over point-to-point links.
This document describes the use of ATM Adaptation Layer 2 (AAL2) for
framing PPP encapsulated packets.
This specification is intended for those implementations which desire
to use the facilities which are defined for PPP, such as the Link
Control Protocol, Network-layer Control Protocols, authentication,
and compression. These capabilities require a point-to-point
relationship between the peers, and are not designed for the multi-
point relationships which are available in ATM and other multi-access
Thompson, et. al. Standards Track [Page 1]
RFC 3336 PPP Over AAL2 December 2002
PPP over AAL5  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 .
PPP over AAL2 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.
The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD,
SHOULD NOT, RECOMMENDED, MAY, and OPTIONAL, when they appear in this