The role of efficient XML interchange (EXI) in Navy wide-area network (WAN) optimization

Abstract

Navy afloat units become disadvantaged users, once disconnected from the pier, due in part to the high latency associated with SATCOM. Unfortunately recent gains in SATCOM capacity alone do not overcome throughput limitations that result from latency’s effect on connection-oriented protocols. To mitigate the effect of latency and other performance inhibiting factors, the Navy is improving its current WAN optimization capabilities by implementing Riverbed Steelhead WOCs. At-sea testing has shown Steelhead increases effective SATCOM capacity by 50%. Laboratory testing demonstrates that by encoding structured and semi-structured data as EXI rather than XML, compression ratios can be further improved, up to 19 times greater than Steelhead’s compression capability alone. Combining EXI with Steelhead will further improve the efficient use of existing SATCOM capacity and enable greater operational capabilities, when operating in a communications constrained environment. Not only does EXI improve compactness of traffic traveling over relatively high capacity SATCOM channels, it also expands net-centric capabilities to devices operating at the edge of the network that are restricted to lower capacity transmission methods. In order to achieve these substantial improvements the Navy must incorporate the already mandated DISR standard, EXI, as the single standard for all systems transferring structured and semi-structured data.