The market for WAN optimization controllers (WOCs) is maturing rapidly, but demand remains strong thanks to virtualization and server consolidation projects.
That’s certainly the view of Andy Rolfe, a research director at Gartner. “Vendors are moving away from the ‘mine is faster than yours’ approach to selling these boxes because most of them are already doing a good job with acceleration,” he says. “They all offer more or less the same performance gains now, give or take about 10 percent.”
WOCs are used to speed up slow wide area network links to servers using a combination of techniques including:
- data compression, caching, and replication
- traffic management including quality of service (QOS) classification and traffic shaping
- general protocol acceleration
- application specific traffic acceleration
The fact that WOCs are well understood and proven to work means they are an obvious purchase when virtualization and server consolidation initiatives lead to servers being removed from branch offices and run centrally in corporate server rooms or data centers. But they are becoming popular in other circumstances too: Two areas where WOCs are becoming increasingly common are at the very high end, connecting multiple data centers together for backup and redundancy purposes, and the very low end, connecting mobile users and teleworkers to corporate servers to improve the performance of the applications they run.
As a result the form that WOCS are taking is beginning to change. Data center to data center WOCs responsible for high-bandwidth links are increasingly powerful hardware appliances, while branch office WOCs may be hardware appliances, or virtual appliances running on general purpose computers. Eventually it’s possible that WOC functionality will be moved to the branch office router.
At the bottom end there is a trend toward software WOCs running on end-user machines, often with a more limited functionality than dedicated hardware WOCS. “There is definitely a need for soft WOCs,” says Rolfe. “If an organization has centralized its file servers then even an 8 meg DSL line will be slow at bringing data across, and a high bandwidth line doesn’t really help reduce latency in protocols like CIFS anyway. The availability of soft WOCs is becoming an increasingly important part of the selection process for many companies looking to implement a system.”
Another important selection criterion is the specific accelerations that are available for particular applications. Most WOCS provide CIFS and HTTP acceleration, and acceleration for applications such as SQL and Oracle, and to a lesser extent SSL encryption is also commonplace. “Vendors are moving up the stack,” says Rolfe. “People are interested in VDI, and we often get inquiries about a particular app like AutoCAD.”
One trend that is emerging is a resurgence of interest in QoS and traffic management, reporting and control. Interest in this was high a decade or more ago, but that subsided as many organizations became more interested in data compression and caching. “It certainly seems like the primary thing that companies are interested in when they have pain is accelerating the traffic. But QoS and bandwidth management seems to be the next step to acceleration: companies are looking at how they can measure, monitor and predict traffic after they have accelerated it so they don’t run in to performance problems again,” says Rolfe. As part of this trend Blue Coat Systems, a market leading acceleration company, bought Packeteer, a leading traffic management vendor, in mid-2008, while Riverbed Technology, another market leader in the acceleration space, bought Mazu Networks, another leading name in the network and application monitoring and control market, in January this year. Just about all the other major acceleration vendors also now offer traffic management functionality of some sort as well.
The falling costs of bandwidth may also have an effect on the market as WAN links are likely to increase in capacity. More bandwidth may alleviate some existing problems, but certainly not all of them—especially problems caused by latency. So although many organizations may find they have higher bandwidth WANs at their disposal, they will still look to WOCs for performance gains with applications that use “chatty” protocols.
Performance gains from WOCs can be significant—application response times can be improved by a factor of ten or more thanks to the use of some acceleration technologies in some circumstances. And Rolfe believes that new trends will make them even more important over the coming months and years. “As cloud computing and Web 2.0 type applications become more common place, there will be an increasing opportunity to benefits from these devices as well,” he says. And that means the need for WOCS in most organizations looks set to remain strong for some time to come.