Intel® IXP400 Software

Access-Layer Components:

ATM Driver Access (IxAtmdAcc) API 4

This chapter describes the Intel® IXP400 Software v2.0’s “ATM Driver-Access” access-layer component.

4.1What’s New

There are no changes or enhancements to this component in software release 2.0.

4.2Overview

The ATM access-driver component is the IxAtmdAcc software component and provides a unified interface to AAL transmit and receive hardware. The software release 2.0 supports AAL 5, AAL 0, and OAM. This component provides an abstraction to the IXP4XX product line and IXC1100 control plane processors’ ATM cell-processing hardware. It is designed to support ATM transmit and receive services for multiple ports and VCs.

This chapter describes the configuration, control, and transmit/receive flow of ATM PDU data through the IxAtmdAcc component.

The general principle of improving performance by avoiding unnecessary copying of data is adhered to in this component. The BSD-based buffering scheme is used.

Since AAL 0 is conceptually a raw cell service, the concept of an AAL-0 PDU can be somewhat misleading. In the context of software release 2.0, an AAL-0 PDU is defined as containing an integral number of 48-byte (cell payload only) or 52-byte (cell payload and cell header without HEC field) cells.

4.3IxAtmdAcc Component Features

The services offered by the ixAtmdAcc component are:

Supports the configuration and activation of up to 12 ports on the UTOPIA Level-2 interface.

Supports AAL-5 CPCS PDUs transmission service, which accepts fully formed PDUs for transmission on a particular port and VC. AAL-5 CRC calculation is performed by hardware. (PDUs may consist of single or chained IXP_BUFs.)

Supports AAL-0-48 PDU transmission service, which accepts PDUs containing an integral number of 48-byte cells for transmission on a particular port and VC. (PDUs may consist of single or chained IXP_BUFs.)

Programmer’s Guide

IXP400 Software Version 2.0

April 2005

 

Document Number: 252539, Revision: 007

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Intel IXP400 manual Access-Layer Components ATM Driver Access IxAtmdAcc API, IxAtmdAcc Component Features