When designing a storage area network (SAN) to meet a customer’s needs, one of the most important choices is to determine the type of connectivity to use: FRC (Fibre Channel) or iSCSI (Internet Small Computer System Interface)? Each has advantages and disadvantages and each makes sense in different situations.

The Fibre Channel protocol tends to be the best for bandwidth-intensive applications. However, many believe that most applications and storage architecture cannot take advantage of all the bandwidth that Fibre Channel delivers today.

The cost of implementing a Fibre Channel SAN can cause companies to look at iSCSI as an alternative solution. In some cases, the Fibre Channel SAN makes sense simply because the customer already has FC implemented within their enviroment and the learning curve is often very small.

Over the past few years, the iSCSI protocol has come into its own, proving to be a good alternative for connecting an organization’s servers to network storage, especially in smaller distributed environments like branch offices or remote locations. iSCSI translates into simpler storage management and consolidation at a reasonable cost. The plug and play nature of iSCSI-compliant products allows organizations to deploy IP-based SANs rapidly.

Concerns about iSCSI performance have been discounted, eliminating yet another roadblock to the adoption of iSCSI as a valid SAN connectivity option. It has been found that for disk intensive real world applications, the difference between iSCSI and FC performance is negligible.

NexSAN is an example of a storage manufacturer that in the past offered its SATABoy and SATABeast with dual Fibre Channel connectivity. iSCSI connectivity was added to the same controller since there was a significant request for support of the iSCSI protocol. Another example of the need to support both protocols comes from StoreVault, a NetApp company. NAS and iSCSI are standard protocols supported on every S500 that ships from StoreVault. The S500 will soon support Fibre Channel connectivity, upon the release of the fibre card by StoreVault.

It is important to determine the customer’s expectations regarding performance demands or needs. If the environment is distributed, performance may be of lesser priority (iSCSI); however, for a data center offering something that is very throughput-intensive, the only solution may be a Fibre Channel-based SAN. It would not be uncommon for an organization to implement both Fibre Channel and iSCSI, and they both have their place in the market.

About the Author
Christine Harrell is a writer for Sunstar Co., a company specializing in disk storage and data backup.