According to a recent IDC report, the market for WAN optimisation solutions is growing at about 19 percent every year and is likely to reach $610m by 2009. That’s because more than half of enterprise staff now routinely access mission-critical apps from remote offices where, despite the ready availability of high-speed broadband, the link between the branch office and the datacentre can still be a bottleneck.

Part of the problem is the way apps are written, with the general assumption that they will be on high-speed local area networks with minimal latency and few other problems. However, short of re-engineering apps to work better over low-bandwidth, high-latency WAN links, there are a number of ways to overcome the difficulties.

Most of these strategies involve appliances (or software) to compress the data being squirted down the line, with a matching appliance at the remote site to decompress and put it all back together again. The same appliances can also accelerate network protocols, for example, by using large frame sizes over the WAN link and providing local acknowledgment facilities. Plus they can also provide additional application-specific optimisation for common programs such as Microsoft Office, Exchange and most client/server database systems.

The market for WAN optimisation products is crowded with vendors. According to the IDC report, Worldwide WAN Optimisation Management 2005-2009, the leader is Packeteer with its iShaper and PacketShaper appliances, followed by Peribit, now part of Juniper Networks, and Allot Communications. Cisco, Nortel and now Microsoft also want a piece of the market.

Citrix acquired Orbital Data last month for Orbital’s optimisation technology, which accelerates applications delivered by Presentation Server and other Citrix products. Plus it’s a network-transparent system that doesn’t interfere with quality of service (QoS) and other mechanisms important in converged voice and data networks, which are fuelling demand for WAN optimisation solutions.

Citrix has already assimilated Orbital’s technology into its WANScaler system. And less than a month after the acquisition, Cisco has announced an agreement with Microsoft to jointly develop a branch office appliance combining the WANScaler optimisation technology with Microsoft’s Internet Security and Acceleration server.

Microsoft is clearly keen to get a slice of this market as are most of the other big names, and partnering with a specialist developer like this is a good way to do this. So you can expect more joint developments and a good deal of consolidation in the WAN optimisation field in the coming months.