Expand Networks adds WAFS support

New gear caches files locally, syncs with central servers.

Expand Networks this week is expected to announce support for wide-area file services that can help businesses save money by consolidating servers into data centers rather than maintaining servers at branch offices.

To accomplish this, Expand is introducing three Expand Accelerator hardware appliances, as well as software designed to boost the speed of Microsoft-based file transfers. The hardware includes hard drives for caching frequently and recently used files locally so they don't have to cross the WAN each time they are accessed.

The software synchronizes changes made in branches with the master files stored on central servers so the next person to access the file gets the current version. To sync files, the devices send only the data that changed, not the entire file, minimizing how much data crosses the wide-area connection.

The software accelerates Microsoft's Common Internet File System (CIFS) protocol that is used for transferring files. CIFS is designed for use on LANs, and its chatty nature tends to slow traffic on WANs because each back-and-forth exchange has to cross constricted links that are subject to congestion and network delay.

Other vendors such as Riverbed Networks and Swan Labs are adding WAFS capabilities to their products, which were originally designed to make more efficient use of WAN links for general traffic, says Joe Scorupa, an analyst with Gartner. WAFS is geared for optimizing file transfers across the WAN, and Tacit Networks is specializing in it, he says. Cisco, Juniper and HP are adding WAFS technology to their lineups, Scorupa says, and might wind up supporting WAFS with blades in routers.

One Expand customer that already used its WAN acceleration appliances to speed links between its data center in Missouri and call centers in Jamaica and Panama is considering the new Expand devices for their WAFS capabilities that would let the company consolidate its servers.

The devices would allow the company to pull servers out of the call centers where supervisors write and store reports and instead centralize them at the data center, says Andy Ellsworth, network engineer for National Asset Recovery Services in Chesterfield, Mo. "It would be nice to have the data secured in the [U.S.] and cached on the Expand boxes as a way to give supervisors access remotely," he says.

Expand Netwrorks' AcceleratorThe new Expand gear might help further reduce National Asset Recovery's cost of remote equipment maintenance by replacing DNS, DHCP and print servers, all of which are integrated in the new Expand devices, Ellsworth says.

The Expand boxes also optimize traffic between Citrix client machines and servers, boosting performance across WANs. For businesses that use Citrix to reduce the number of servers in their networks, as well as the number of full application clients on PCs, this can boost performance. Ellsworth says he runs Citrix traffic over Expand Accelerators and they cut WAN traffic by a third. He says he expects further but less dramatic reductions with the Citrix software.

Expand's gear can be deployed to support both WAN optimization and WAFS, or just one of them. The new Accelerator hardware supports both, and the old Accelerator supports just WAN optimization, the company says. It will continue to sell both.

Businesses sometimes want these functions separated because the WAN optimization is handled by network groups and WAFS is handled by storage groups. Keeping the devices separate prevents the two groups from conflicting, Gartner's Scorupa says.

The three new Expand appliances, Accelerator 4920, 6910 and 6940, are in beta testing. The 4920 supports up to 2M bit/sec links, 10 remote sites and has a 160G byte hard drive. Pricing starts at $4,500. The 6910 supports up to 10M bit/sec links, 50 remote sites and has a 400G byte hard drive. Pricing starts at $12,000. The 6940 supports links up to 20M bit/sec, 200 remote sites and has a 400G byte hard drive. Pricing starts at $20,000.

Learn more about this topic

Tacit gear optimizes WAN traffic


Storage networks get help from WAN accelerators


Why WAFS could be critical to performance


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