How WAN optimisation works
Article Date: Mar 14 2008It’s not uncommon for a corporate litigator in the New York office of a law firm to be working on the same case as colleagues in New York or Brussels – sometimes over many years. The only problem is that the case notes the different groups are reviewing and updating over their wide area network (WAN) can amount to 100MB or more.
The same goes for engineering drawings, patient records and a film studio’s ‘rushes’. Companies with an international presence often struggle with the sharing of large files and the performance of server-based applications.
The practical solution is WAN acceleration, where the aim is to provide local area networking-like access to data and applications anywhere within the enterprise network, allowing for real-time collaboration for users in branch offices and even mobile workers around the world.
Accelerators are pizza box-sized devices that sit at either end of the WAN connection, addressing the three main problems that plague WANs (slow delivery, low bandwidth, and ‘chatty protocols’). A case in point is the ‘common internet file sharing’ protocol (CIFS) used by Windows applications to gain access to remote files. Each time a user wants to open a Windows file over a network, multiple messages flit across the network: for a Word document roughly 1MB in size as many as 1,500 messages might be swapped in opening the file.
Scores of specialist technology vendors have sprung up in recent years to address
the demand to get round the limitations of networks. IT industry adviser Gartner singles out Riverbed Technology, Blue Coat Systems, Juniper Networks and Expand Networks as the sector’s leaders.
Their clients are seeing some real gains. A US law firm shelled out $69,000 (£34,000) for Riverhead’s Steelhead WAN accelerator, plus $16,000 a year in related expenses. The firm estimates it has made an eye-popping $980,000 in productivity gains annually by slashing the time attorneys were previously kept waiting for files.
‘Litigation case files which took 22 minutes to download can now be downloaded in two and a half minutes. No amount of added bandwidth could do that for us,’ says Frank Gillman, the firm’s director of technology.
Whether such a time saving from WAN acceleration amounts to 20 minutes less billable time for the client is another matter.
