Motorola PowerQUICC II MPC8280 Series Reference Manual page 1169

Chapter 33
ATM AAL2
The functionality described in this chapter is not available on
the MPC8270.
Refer to www.motorola.com/semiconductors for the latest
RAM microcode packages that support enhancements.
The microcode implementation of the ATM adaptation layer type 2 (AAL2) on the
MPC8280 is compliant with the ITU-T recommendations I.363.2 and I.366.1. This chapter
describes the functionality and data structures of AAL2 CPS, CPS switching, and SSSAR
and should be used as a supplement to Chapter 31, "ATM Controller and AAL0, AAL1, and
AAL5."
33.1 Introduction
AAL2 enables the multiplexing of voice and data channels over a single ATM VC. The
channels consist of packets transported within individual ATM cells (see Figure 33-1).
Packet lengths are allowed to vary in order to accommodate bandwidth fluctuations of the
individual channels. Each packet has a channel identifier (CID) so that each AAL2 user
(channel) is uniquely identified by the triplet VP | VC | CID.
ATM header
MOTOROLA
Freescale Semiconductor, Inc.
NOTE
SSSAR SDU
PH PP
STF PH PP
ATM cell
STF PH PP
Figure 33-1. AAL2 Data Units
Chapter 33. ATM AAL2
For More Information On This Product,
Go to: www.freescale.com
SSSAR PDU
PH PP
CPS PDU
PH PP
PH PP
SSSAR
CPS
Padding
ATM
Padding
33-1