Research And Implementation Of WAN Application Layer Protocol Acceleration

To meet the needs of informationization of cross-area enterprise branches office, more and more enterprises adopt the WAN as the data transmission channels when establishing centers of information service. So the performances of the application based on WAN are highly concerned by enterprises. In recent years, the work of the WAN optimization is mainly focused on the transport layer protocol. However, the practical application shows that the behavior of application layer protocols plays a more important role in the actual performance. This paper analyses behaviors of application layer protocols and designs a solution to improve the WAN application performance experience.Building a WAN test bed, this thesis tests several typical application layer protocols performance in the WAN. The results show that the high propagation delays in WAN have a huge negative impact on the application layer protocol performance. For this reason, this thesis designs an extensible WAN application acceleration gateway, named E-WAAG, to improve the transporting performance on the application protocols.E-WAAG is an inversion of control framework, which adopts event-driven as its control models. A session model is designed for E-WAAG in order to offer interfaces for application data processing, which is the foundation of implementation for data pre-fetch based on transaction prediction, also a tunnel implementation model is proposed, which provides a platform for end-to-end WAN optimization solution.Finally, we developed an Exchange accelerator based on E-WAAG, called MapiAcc. The experiments indicate that the transmission rate of a bulk email with large attachments is 2 to 3 times faster by using MapiAcc, and the effect is more evident on the network with higher transmission latency.