Citrix bought a company called Orbital Data back in July 2006 which ultimately led to the creation of Citrix’s WANscaler line of appliances. This was the first time I really started paying attention to proper WAN accelerators or WAN optimizers. Sure, I’d been using Packeteer (and Sitara and Allot) for years for basic Quality-of-Service shaping to protect ICA on the network, but the whole concept of a device that accelerates TCP connections, caches and dedupes network traffic, and generally makes a WAN work better was new to me in 2006.
(I did a session called “Optimizing and understanding Citrix over WAN connections” at BriForum 2008 Chicago last year. You can watch that video online to learn more about how this stuff works. That video applies to all WAN vendors—not just Citrix WANscaler.)
In the past, I’ve written about how cool it would be if Citrix really embraced these and changed the behavior of XenApp to more appropriately work with WANscalers. (More details on that.) Unfortunately that hasn’t happened from Citrix yet, but at this point it doesn’t really matter. There are a lot of really great WAN optimization vendors that have some cool products that can really help in the desktop and application virtualization space today. I’m most familiar with Expand Networks, although I just met with Riverbed last week and I’m looking forward to speaking with the others very soon. (Expand was at BriForum last year, which is why I know them so well. Here’s my interview with them from the show.)
In my quest to meet with all 113 desktop virtualization vendors this year, I talk to a lot of vendors who are very closed-minded about the future of our industry, (mainly because they only make products that fit certain use cases, so they try to shoe-horn every real life situation into the use case that they happen to have a product for). But the WAN optimization vendors are different, because regardless of whether your technology is server-based or client-based, streamed or local, virtual or not—if you have users outside of your corporate headquarters, then you’re dealing with a WAN.
For strict server-based computing (whether VDI or Terminal Services), all these WAN optimizer products work in the same way, which is that in addition to their standard TCP optimization capabilities, you disable encryption and compression of your remote display protocol at the server-level which lets the WAN optimizer go to work looking for duplicated data chunks which can be cached on the remote ends. While just about every vendor has a software client for mobile users today, these optimizers really shine in remote offices where you have more than one user connecting into the same server-based apps. In this case, all the little screen graphics and GDI data can be cached from multiple users, and really the sky’s the limit for how much optimization can be done. (These things really benefit from the economies of scale. The more remote users you have, the more bandwidth they can save you.)
So that’s fine for server-based computing. But don’t forget that the WAN optimizers also help with application virtualization and application streaming, since they can automatically locally cache the application virtualization source packets on the remote side of the WAN. The same is true for all the data you access within a session, such as users’ home drives and profiles. And if you get into the client hypervisor or local virtual desktop space, the WAN accelerators will do a great job caching the VHD or VMDK files.
The bottom line is that as you evolve from pure client-based computing to server-based computing to application streaming to offline or local VMs to OS streaming…. These WAN accelerators can help you the entire time. And with Citrix WANscaler, Expand Networks, Riverbed, Silver Peak, BlueCoat, and probably a dozen others, there’s plenty of competition in this space to ensure that you can get exactly what you want without being ripped off. All of these vendors offer evaluation programs, so it’s pretty easy to borrow a pair of devices and drop them in place to see if they work in your environment. I know in a lot of cases, the cost for the WAN appliance was offset by the fact that they didn’t have to buy a bigger WAN pipe or that they could remove local fileservers from the remote site.
So what do you think? Can anyone share stories about WAN acceleration in your own environment, good or bad?