Many papers have been written on the effect that limited bandwidth and high latency have on application performance across the Wide Area Network (WAN). The purpose of this document is to address a less commonly understood WAN challenge that can also affect the performance of critical business applications – packet loss and reordering.

While packet loss and out of order packets are a nuisance for a network that supports typical data applications1 like file transfer and email, it is a very serious problem when performing data replication and backup across the WAN. The former involves thousands of short-lived sessions made up of a small number of packets typically sent over low bandwidth...