RealTime IT News

Video Streaming Over iSCSI Realized

Working on the premise that the video streaming sector is about to take off like a rocket, two tech companies Monday claimed victory in showing how a streaming video application can be sent over an iSCSI SAN.

Data storage access provider Adaptec and computer maker NEC demonstrated the technology at the most recent Data Storage EXPO in Tokyo.

The new technique is expected to help foster better delivery of streaming video applications, which are very storage intensive. The two companies say the demo illustrates the viability of iSCSI for real end-user deployment. The first installations could come as early as this year.

"Driving iSCSI adoption this year will require a commitment from vendors to deliver complete solutions to market," said Yuzo Oomori, general manager of the System File Product Division at NEC. "We are pleased to partner with the industry leader, Adaptec, to drive compelling iSCSI solutions."

"Streaming video is a perfect example of an application type well suited to iSCSI -- it just works better," said Enterprise Storage Group senior analyst Steve Duplessie. "The more targeted the players get, the more adoption will increase. I like it."

An alternative to Fiber Channel over IP (FC/IP), iSCSI-based storage networking enables block storage data to be transmitted via TCP/IP and Ethernet through the Internet. FC/IP may only be used in conjunction with Fiber Channel technology while iSCSI can run over existing Ethernet networks, making it more cost-effective. The flexible interoperability of iSCSI, coupled with the heralded performance of Ethernet and TCP/IP are leading factors that make the technology so attractive to developers.

In fact, research firm Gartner Dataquest said it believes the iSCSI initiator market will increase from a 2002 market value of $590 million to $1.22 billion in 2005.

Over the past several months, Milpitas, Calif.-based Adaptec has demonstrated several iSCSI applications, including back-up, remote mirroring, and Fibre Channel extension, with such partners as Cisco, ADIC, Eurologic, Veritas and SpectraLogic.

Adaptec's storage networking products include a family of IP Storage ASICs and adapters with protocol acceleration for iSCSI, FCIP, FC-iSCSI, and TCP/IP connectivity; and the industry's first iSCSI HBA. Adaptec's IP Storage technology is currently being designed into products from several OEMs, including IBM , ADIC, INRANGE and McData.

How iSCSI Works
When an end user or application sends a request, the operating system generates the appropriate SCSI commands and data request, which then go through encapsulation and, if necessary, encryption procedures. A packet header is added before the resulting IP packets are transmitted over an Ethernet connection.

When a packet is received, it is decrypted (if it was encrypted before transmission), and disassembled, separating the SCSI commands and request. The SCSI commands are sent on to the SCSI controller, and from there to the SCSI storage device. Because iSCSI is bi-directional, the protocol can also be used to return data in response to the original request.

iSCSI is one of two main approaches to storage data transmission over IP networks; the other method, Fibre Channel over IP (FCIP), translates Fibre Channel control codes and data into IP packets for transmission between geographically distant Fibre Channel SANs. FCIP (also known as Fibre Channel tunneling or storage tunneling) can only be used in conjunction with Fibre Channel technology; in comparison, iSCSI can run over existing Ethernet networks.

A number of vendors, including Cisco , IBM, and Nishan have introduced iSCSI-based products (such as switches and routers).