On Source Rules for ABR Service on ATM Networks with Satellite Links

TL;DR

This paper analyzes and improves ABR traffic management over satellite links in ATM networks, leading to specific protocol modifications that significantly enhance throughput from 45 Mbps to 140 Mbps.

Contribution

It identifies issues with source rules in ATM ABR service over satellite links and proposes modifications that are incorporated into the ATM TM 4.0 specification.

Findings

Throughput over satellite links increased from 45 Mbps to 140 Mbps.

Adjustments to Crm and TBE parameters improved ABR performance.

Changes are now part of ATM traffic management standards.

Abstract

During the design of ABR traffic management at the ATM Forum, we performed several analyses to ensure that the ABR service will operate efficiently over satellite links. In the cases where the performance was unacceptable, we suggested modifications to the traffic management specifications. This paper describes one such issue related to the count of missing resource management cells (Crm) parameter of the ABR source behavior. The analysis presented here led to the changes which are now part of the ATM traffic management (TM 4.0) specification. In particular, the size of the transient buffer exposure (TBE) parameter was set to 24 bits, and no size was enforced for the Crm parameter. This simple change improved the throughput over OC-3 satellite links from 45 Mbps to 140 Mbps.