Blue Coat ProxySG 200B

WAN optimisation has traditionally been beyond the means of the smaller branch office or business, but this new product partnership from Blue Coat aims to deliver an affordable solution that also targets remote users.

The ProxySG 200B on review may represent the entry point of Blue Coat's appliance family, but it delivers the same features as found in its bigger brothers. It functions as a transparent TCP proxy that intercepts and optimises all TCP traffic, and offers a range of features including bandwidth management, protocol optimisation and compression, plus Blue Coat's own byte caching. In small installations, the appliance is placed at the head office, but Blue Coat's SG Client software does away with the need for hardware at the other end. This is deployed on each client system, whether in a remote office or on the road.

There are a few limitations, as the client doesn't currently support byte caching, so it's unable to send deltas. If you modify a file or copy it from a client, it will have to send the whole thing down the wire. The client also can't optimise HTTPS traffic, which is a feature that makes the SG appliances stand out from much of the competition. However, it can carry out TCP optimisation and object caching, and for the latter it will use up 10% of local storage - a default value that can't currently be modified.

For testing, we used the Labs' resident Network Nightmare WAN simulator (www.networknightmare.com) configured for a 1Mb/sec WAN link with an 80ms round-trip latency. We placed the ProxySG on one side and added a Windows Server 2003 R2 domain controller configured with Ipswitch's IMail Server 8. On the other side, we placed a Windows XP SP2 client and used a 4.8MB PowerPoint presentation to test a variety of scenarios. Do disable SMB signing on your central servers, as this will cause performance problems.

With optimisation turned off, remotely opening the file at the client end using PowerPoint took 72 seconds, and saving a small modification to the server took 43 seconds. With the agent activated, the file took 46 seconds to open, and with it now cached locally subsequent file opens took a mere seven seconds. We noted that saving file modifications still took 42 seconds, and Blue Coat advised us this was due to the lack of support for byte caching.

Mailing the file as an attachment from the client to the server with no optimisation took 2mins 8secs, while receiving the same file to the client took 59 seconds. With the agent active and the file cached, the same operations took 37 and 57 seconds respectively. Simple file-copy operations also saw significant improvements, with the presentation copied from client to server and back again in 50 seconds and 54 seconds respectively, and only 36 seconds and a mere 0.5 seconds with the agent activated and the file cached.

This Blue Coat partnership isn't a perfect match at present but, for the price, it does delivers some useful WAN optimisation features. It's particularly easy to deploy, and the agent makes it equally valuable to remote workers and small branch offices.

Author: Dave Mitchell