Expand Network's has developed a Lotus-specific module for its WAN accelerators which it claimed can accelerate Notes and Domino applications by a factor of 10 or more. The company said it would allow Notes-using organisations to eliminate regional email servers and consolidate their Domino servers at HQ.

The new software aggregates Notes sessions together to save bandwidth and uses Layer 7 quality-of-service controls to prioritise Lotus apps over others, as well as compressing data and tweaking TCP to improve remote data replication.

Nat Smith, Expand's director of product marketing, said that while packet aggregation is a widely applicable technique, its implementation in this case required specific knowledge of how the applications communicate.

"Knowing specifically how Notes and Domino communicate, it made sense to extend this technology for use with this application," he added.

"Notes and Domino are not always well suited to the WAN. For example, Notes replication enables off-line access to data with unprecedented flexibility. However, the network load generated by data synchronisation, once back on-line, can easily cripple other traffic and processes.

"In addition, the built-in Domino compression features tend to have a large scaling impact on the servers, as they sap precious CPU cycles away from other hungry real-time processes."

The need for application-specific modules to speed up applications over the WAN is reminiscent of a few decades back, when software developers needed to understand how the mainframe worked, and even how it wrote data to the hard disk, in order to squeeze maximum speed out of the system.

So were the Lotus development team wrong in not optimising for remote access when they designed their code? Not according to Smith.

"Everything tends to be a bit of a trade-off," he said. "If you build an application for the WAN, it would tend to be much less interactive, friendly and feature-rich; however, if you build the application without consideration of the WAN, then all of the feature benefits would be for not, as the application becomes unusably slow.

"Most application developers, including Lotus, have figured this out, and compromise with some features and slightly worse performance over the WAN. The shift comes with a WAN optimisation solution that transparently changes the environment for the application, removing congestion and mitigating latency."

Notes users have repeatedly - and unsuccessfully - called for Lotus to develop a multi-threaded client that doesn't stall when given a single heavy task to perform, but Smith suggested that the Expand software could provide some of the same benefits.

"Most applications - Notes and Domino included - perform well on the LAN the way they are," he said. "At the highest level, WAN optimisation is seeking to reverse the ill-effects of the WAN, allowing applications to perform as they do on the LAN. The net result is performance that works for the user."