RACK for SCTP

Abstract

RACK for TCP is a loss detection and recovery algorithm which relies on the notion of time instead of counting packet losses. The algorithm has been integrated in Microsoft Windows, Linux and FreeBSD as a full-featured alternative to the existing TCP loss recovery algorithms. Cheng et al. claim that the algorithm offers a significant improvement, especially for tail losses and cases with packet reordering within the network. We adopted RACK for the SCTP protocol and improved its mechanisms by utilizing built-in SCTP specific features. To evaluate the benefits and drawbacks of RACK and our modifications to the algorithm, we integrated RACK in the SCTP model of the OMNeT++/INET simulation environment. Our simulations show a positive impact in common networking scenarios regarding loss recovery and reordering tolerance.