Worst Case Buffer Requirements For Tcp Over ABR

TL;DR

This paper analyzes the worst-case buffer requirements for TCP over ATM ABR networks, demonstrating that the ERICA+ switch algorithm effectively controls maximum queue lengths even in extreme traffic scenarios.

Contribution

It extends previous work by modeling worst-case scenarios and showing that ERICA+ can manage buffer requirements under these conditions.

Findings

ERICA+ controls maximum queue lengths in worst-case scenarios

Analytical and simulation results support buffer requirement estimates

Buffer control is effective even with high congestion windows and cell rates

Abstract

ATM (asynchronous transfer mode) is the technology chosen for the Broadband Integrated Services Digital Network (B-ISDN). The ATM ABR (available bit rate) service can be used to transport ``best-effort'' traffic. In this paper, we extend our earlier work on the buffer requirements problem for TCP over ABR. Here, a worst case scenario is generated such that TCP sources send a burst of data at the time when the sources have large congestion windows and the ACRs (allowed cell rates) for ABR are high. We find that ABR using the ERICA+ switch algorithm can control the maximum queue lengths (hence the buffer requirements) even for the worst case. We present analytical arguments for the expected queue length and simulation results for different number of sources values and parameter values.