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New York, NY May 04, 2005

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An Overview of the Wide Area File Services Market

contributed by John Herron

What are Wide Area File Services

For companies that have small branch offices (and generally no IT administration at these sites) it is a difficult chore to manage storage at remote locations, as well as support local backups at each site. To address this issue many companies have been looking to Storage Area Network (SAN) solutions to centralize all the corporate files. While this solution resolves the storage and backup issue, users at the branch offices suffer the performance issue of opening files across the Wide Area Network (WAN), particularly in Windows environments where the CIFS (Common Internet File System) protocol used to access remote files is chatty and inefficient. In order to address the performance issues related to accessing files across WAN links a new industry of products has developed, known as WAFS (Wide Area File System).

Although the mechanics and protocols for creating a WAFS solution differs from vendor to vendor, there are some similarities. Each vendor relies on a set of appliances, one at the central site and one at each of the branches. These appliances communicate with one another as gateways that replace the CIFS (or NFS (Network File System) in Unix environments) protocol, streamlining the communication between branch and central office and improving the end-user response time. These appliances improve the performance in three ways: 1) By replacing the chattier protocol with a more efficient one they reduce WAN traffic 2) Each provides compression techniques to reduce the amount of data that crosses the WAN 3) By caching recently used files, users in the branches receive local area network performance rates on these files. Varying cache sizes are available.

When a user accesses a file that only resides at the central location, he or she will see some latency when opening the file, but due to the optimized protocol and compression, it will be faster than accessing the file without the use of the WAFS system. When subsequent users, at the same branch, access the same file, or the original user writes changes to the file the response will be the same as if he or she were accessing a local file server.

Players in the Market

As this is a relatively new technology, there are four main vendors in the WAFS marketplace. Each has a somewhat different approach.

Tacit Networks

The Tacit Networks (www.tacitnetworks.com) product is known as iShared and comes in an iShared Server, used at the central site, and iShared Remote, used at each of the branches. Tacit uses their own proprietary protocol called SC/IP (Storage Caching over IP) to communicate between appliances.

DiskSites

DiskSites (www.disksites.com) works similarly with FilePort being the centralized device and FileController being the branch device. This product offers DNS and DHCP services in addition to file services. Unlike Tacit which requires users to access shares against the local appliance, such as \\localserver\share, DiskSites uses a dynamic global file system, so users throughout the organization access a single share name, such as \\organization\share.

Riverbed Technology

The Riverbed Technology (www.riverbed.com) product, known as Steelhead, is marketed as a product that is not WAFS since it addresses other protocols, such as FTP, Web, and Exchange in addition to file services. Riverbed claims that they have addressed issues that occur with other “caching” solutions so that users are always guaranteed to be working with the master copy.

Cisco

Cisco’s (www.cisco.com) product is called the File Engine and is based on technology they acquired from Actona Technologies in the summer of 2004. A file Engine is required at the central office and each of the branches.

Costs

Though the costs vary from vendor to vendor and are dependent on the number of users and the size of the local cache, consumers can expect to pay roughly $13,000 to $20,000 for the central office and $7,000 to $10,000 for branch appliances.

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