Posted by: Eric Siegel
While I'm thinking about Software as a Service (SaaS) today, how about WAN Performance Optimization for SaaS?
Some SaaS websites are well-designed for the Web and perform well over poor bandwidth and high latency, but others don't, or they require the upload/download of large files. For those situations, WAN performance optimization can make the difference between usable and useless. (See, for example, my blog entry "Be a Hero! Cut costs to Zero!" for a discussion of optimization.)
Indeed, if you've created performance indicators in your service level agreement (SLA) with the SaaS provider, they may be more than happy to work with you to install WAN performance optimization between their server sites and your users. (See my blog entry "SaaS network performance SLAs.")
So. How should you install WAN optimization? There are a few things to keep in mind as you discuss this with your SaaS provider.
First, if your SaaS provider wants to use a double-ended appliance system (i.e., an optimizer appliance at the SaaS server site and an optimizer appliance at your site), how are you going to configure the device and integrate it into your branch offices? What happens if you have more than one SaaS provider? Will there be a tall, tottering stack of WAN optimizers from different vendors, and a maze of Ethernet cables plugging everything together? If the "appliance" at the branch office is a software application, how will you load it into your branch office server, and will it conflict with other software?
Third, even if your SaaS provider doesn't want to install WAN optimization, you may still be able to improve performance with a branch office cache that will store commonly-downloaded files for use by all browsers in the office. Many branch office optimizers -- such as those that you might be using for communications with your central office -- can provide caches, as can Web traffic filtering devices, such as Blue Coat's ProxySG. Of course, there are also free caches, such as Squid; they can run on an inexpensive Unix or Windows box and make a big difference if you have a lot of users accessing the same set of Web files.