Products / Solutions > New Technologies

FCIP
Grid Computing
iFCP
iSCSI
Serial ATA
Serial Attached SCSI


FCIP (Fibre Channel over IP)

As organizations increasingly face an enormous influx of data that must be stored, protected, backed up, and replicated, they have turned to Storage Area Networks (SANs) to manage these tasks in an efficient, cost-effective manner. Fibre Channel SANs address the need to protect data while making it available to a wide variety of users who demand anywhere, anytime data access.

To ensure that this data reaches all the users who need it, organizations are now looking for new ways to transport data throughout the enterprise—locally over the SAN as well as over much longer distances. One of the best ways to achieve this goal is to interconnect geographically dispersed SANs through reliable, high-speed links.

This approach involves transporting Fibre Channel block data over existing IP infrastructures currently used throughout the enterprise. The new FCIP protocol standard has rapidly gained acceptance as a manageable, cost-effective way to blend the best of both worlds: Fibre Channel block data storage and proven, widely deployed IP infrastructure. As a result, organizations now have an excellent way to protect, store, and move their data while leveraging existing technology investments.

Benefits of FCIP

While multiple technologies are capable of interconnecting SANs, very few can be widely deployed in a cost-effective manner today. Because most organizations already have IP connections and significant experience with Ethernet and IP networks, they can usually leverage this equipment and expertise to help manage data in conjunction with Fibre Channel SANs. For example, IP connectivity provides the greatest flexibility at the lowest cost for latency-tolerant applications. As a result it can be used to back up data across a campus network, Metropolitan Area Network (MAN), or WAN. Moreover, this flexible technology can be deployed within a single enterprise or in an SSP multi-tenant environment.

Today, many types of organizations are beginning to transport SAN storage over IP, especially for non–real-time data transfer. By combining the best of two mature technologies, FCIP solutions provide a more standardized and lower cost way to

increase SAN interconnectivity for a variety of applications. In fact, FCIP includes full support for the Fibre Channel set of equipment and software. Organizations can seamlessly extend existing and planned Fibre Channel SANs over long distances through IP networks—thereby protecting significant investments in both technologies. In addition, FCIP provides a cost-effective way to achieve business protection (enabling such solutions as remote tape archiving).

One of the first implementations of FCIP is the interconnection of disparate SAN islands. FCIP can transport existing Fibre Channel services across the IP network such that two or more interconnected SANs can appear as a single large SAN and can be managed by traditional SAN management applications. In addition, FCIP enables SAN applications to support additional protocols without modification. These applications might include disk mirroring between buildings in a campus network or remote replication over the WAN. The type of applications utilized will be based on the distance the data must travel, the network bandwidth, and the QoS requirements and/or abilities of the network connection.

While some implementations of FCIP are point-to-point “tunnels”, the protocol does not require that the “gateways” support only point-to-point tunneling. The FCIP standard supports all Fibre Channel services, including FSPF routing algorithms, such that multiple logical links created from a single gateway can route Fibre Channel packets over the IP infrastructure. Not only is FCIP routable, but IP networks do not need to know anything about the packets being routed. The Fibre Channel services handle all routing between logical links, while the TCP protocol handles the delivery of packets to the specific gateway device.

back to top


Grid Computing

The GRID is widely seen as a step beyond the Internet, incorporating pervasive high-bandwidth, high-speed computing, intelligent sensors and large-scale databases into a seamless pool of managed and brokered resources, available to industry, scientists and the man in the street. The name, GRID, itself draws the analogy between the pervasive availability of electrical power and that of computing and data, coupled with mechanisms for their effective use.

back to top


iFCP (Internet Fibre Channel Protocol)

The iFCP specification defines iFCP as a gateway-to-gateway protocol for the implementation of a Fibre Channel fabric in which TCP/IP switching and routing elements replace Fibre Channel components. The protocol enables the attachment of existing Fibre Channel storage products to an IP network by supporting the fabric services required by such devices.

iFCP supports FCP, the ANSI SCSI serialization standard to transmit SCSI commands, data, and status information between a SCSI initiator and SCSI target on a serial link, such as a Fibre Channel network (FC-2). iFCP replaces the transport layer (FC-2) with an IP network (i.e. Ethernet), but retains the upper layer (FC-4) information, such as FCP. This is accomplished by mapping the existing Fibre Channel transport services to TCP/IP. iFCP, through the use of TCP/IP, can therefore accommodate deployment in environments where the underlying IP network is not reliable.

iFCP's primary advantage as a SAN gateway protocol is the mapping of Fibre Channel transport services over TCP, allowing networked, rather than point-to-point, connections between and among SANs without requiring the use of Fibre Channel fabric elements. Existing FCP-based drivers and storage controllers can safely assume that iFCP, also being Fibre Channel-based, provides the reliable transport of storage data between SAN domains via TCP/IP, without requiring any modification of those products. iFCP is designed to operate in environments that may experience a wide range of latencies.

Why iFCP?

iFCP is designed for customers who may have a wide range of Fibre Channel devices (i.e. Host Bus Adapters, Subsystems, Hubs, Switches, etc.), and want the flexibility to interconnect these devices with IP network. iFCP can interconnect Fibre Channel SANs with IP, as well as allow customers the freedom to use TCP/IP networks in place of Fibre Channel networks for the SAN itself. Through the implementation of iFCP as a gateway-to-gateway protocol, these customers can maintain the benefit of their Fibre Channel devices while leveraging a highly scaleable, manageable and flexible enterprise IP network as the transport medium of choice.

iFCP enables Fibre Channel device-to-device communication over an IP network, providing more flexibility compared to only enabling SAN-to-SAN communication. For example, iFCP has a TCP connection per N_Port to N_Port couple, and such a connection can be set to have its own Quality of Service (QoS) identity. With SAN-to-SAN communication, varying connections cannot be prioritized over one another.

Using a multi-connection model for TCP is important for iFCP as it provides higher aggregate throughput compared to an implementation of a single-connection model. With the single connection model, a single TCP connection links multiple SAN islands, and therefore multiple N_Port to N_Port sessions. One congestion loss in the connection can disrupt the entire fabric and affect all N_Port to N_Port sessions using that tunnel.

With the multi-connection model of iFCP, congestion loss in one N_Port to N_Port session will only affect the throughput of that session. This model isolates the effects of congestion to specific sessions, without impact to other sessions operating in parallel.

back to top


iSCSI

Remote tape backup and tape vaulting, remote mirroring, storage consolidation, content distribution as well as data centre applications all benefit from the ubiquity, manageability and cost/performance proposition of mainstream IP networking.

SCSI over IP

The Small Computer Systems Interface (SCSI) enables host computer systems to perform block data input/output (I/O) operations to a variety of peripheral devices. Target devices may include disk and tape devices, optical storage devices, as well as printers and scanners. The traditional SCSI connection between a host system and peripheral devices is based on parallel cabling. Parallel SCSI cabling has inherent distance and device support limitations. For storage applications, these limitations have fostered the development of new technologies based on networking architectures such as Fibre Channel and Gigabit Ethernet. Storage area networks (SANs) based on serial gigabit transports overcome the distance, performance, scalability and availability restrictions of parallel SCSI implementations. By leveraging SCSI protocols over networked infrastructures, storage networking enables flexible high-speed block data transfers for a variety of applications, including tape backup, server clustering, storage consolidation, and disaster recovery. The Internet SCSI (iSCSI) protocol defines a means to enable block storage applications over TCP/IP networks.

iSCSI Protocol Model

iSCSI uses TCP/IP for reliable data transmission over potentially unreliable networks. The iSCSI layer interfaces to the operating systems’ standard SCSI set. The iSCSI layer includes encapsulated SCSI commands, data and status reporting capability. When, for example, the operating system or application requires a data write operation, the SCSI CDB (Command Descriptor Block) must be encapsulated for transport over a serial gigabit link and delivered to the target.

The iSCSI protocol monitors the block data transfer and validates completion of the I/O operation. This occurs over one or more TCP connections between initiator and target. In practical applications, an initiator may have multiple target resources over an IP network, and consequently multiple concurrent TCP connections active.

iSCSI Issues

The SCSI protocol demands stability, data integrity and, in current implementations, expects high bandwidth on demand. IP networks, by contrast, are inherently unreliable, may drop packets under congested conditions, and have highly variable bandwidth. The TCP layer is meant to deal with the instability and packet loss that may accompany IP transport, while higher speed wide area connections can alleviate bandwidth issues for block storage data. In addition, the internal mechanisms of the iSCSI protocol provide additional monitoring of TCP connections and for recovering from lost or corrupted command and data PDUs. For high performance storage networking applications, the iSCSI protocol is dependent on several other technologies to make it a viable partner to Fibre Channel SANs. Imposing TCP overhead on servers, for example, is unacceptable for storage applications where server CPU cycles are at a premium. For optimum performance, iSCSI adapters require TCP/IP off-load engines (TOEs) to minimize processing overhead. TCP off-load engines will greatly assist iSCSI’s ability to provide enterprise-class solutions that run at or near wire speeds. Storage applications using iSCSI will also benefit greatly from the introduction of 10 Gigabit Ethernet. Ten gigabit and faster speed Ethernet enables scalable IP SANs that support higher populations of servers and storage devices and a variety of storage applications that can be run concurrently over the same network infrastructure. With TCP off-load engines on servers and large data pipes in the network, iSCSI solutions can achieve an enterprise-ready status for IP-based SANs.

Summary

As a standards draft proposal for IP storage networks, iSCSI presents an end-to-end IP SAN solution. The iSCSI draft specification provides functionality for encapsulating SCSI CDBs and incorporates additional features optimized for TCP/IP networks. This enables enterprise networks to implement homogeneous IP solutions for storage as well as mainstream data communications. Combined with Gigabit and 10 Gigabit Ethernet transports, IP security and quality of service protocols, iSCSI opens new opportunities for highly scalable and secure shared storage networks.

back to top


Serial ATA

Serial ATA is the hottest technology being developed for desktop and low-end server drives today. It gives you easier installations and the power to perform like never before in systems such as

· desktop systems
· high performance PCs & workstations
· low end server
· near-line storage
· consumer electronic devices

Key benefits include

· a blazing 150MB/s interface rate
· enhanced data reliability
· longer thinner cables
· no master/slave jumpers
· snap-in like connectors
· and a blazing 150MB/s speed

Desktops, Mobile PCs, and Consumer Electronics

Serial ATA is an evolutionary replacement for the Parallel ATA physical storage interface. Serial ATA is scalable and will allow future enhancements to the computing platform.

Serial ATA is a drop-in solution in that it is compatible with today's software, which will run on the new architecture without modification. It will provide for systems which are easier to design, with cables that are simple to route and install, smaller cable connectors, improve silicon design, and lower voltages which alleviate current design requirements in Parallel ATA.

Serial ATA supports all ATA and ATAPI devices, including CDs, DVDs, tapes devices, high capacity removable devices, zip drives, and CDRWs. Serial ATA is planned to be the primary storage interface inside the PC system, and is not planned as an external interface to PC storage or peripherals. USB2 and IEEE1394 connections on the PC can be used where required as peripheral interfaces.

Servers and Networked Storage

Serial ATA is a disk-interface technology developed by a group of the industry's leading vendors to replace parallel ATA.

Serial ATA is a viable option for server and NAS networked storage:

Serial ATA technology provides a new serial interconnect designed to change the way vendors develop storage systems. The first deployments, where price is an important issue, are intended for entry-level servers and network-attached storage. As the infrastructure continues to develop, Serial ATA will penetrate into higher-end servers and more complex storage systems.

Serial ATA defines a roadmap starting at 1.5 gigabits per second (equivalent to a data rate of 150MB/s) and migrating to 3.0 gigabits per second (300MB/s), then to 6.0 gigabits per second (600MB/s). This roadmap supports up to 10 years of storage evolution, based on historical trends.

Serial ATA supports legacy drivers for Parallel ATA. OEMs can deploy Serial ATA, today, using existing parallel ATA drivers. Vendors intend to supply bridges for parallel-to-serial conversion for legacy devices.

One of the primary requirements of the Serial ATA 1.0 specification was to maintain backward compatibility with existing operating system drivers to eliminate incompatibility issues.

Because of the legacy support inherent in the specification, operating support will be simplified. The Serial ATA specification allows for additional features to be added to applications. Additional features will be subject to normal driver validation processes.

back to top


Serial Attached SCSI

Serial Attached SCSI products will deliver the next generation of system performance, reliability, scalability and data protection.

To meet the performance needs of next-generation servers, Serial Attached SCSI solutions will feature a roadmap to 12 gigabits/second (1,200MB/s) to optimize system performance for bandwidth-intensive applications in direct-attached, networked-attached and networked storage environments.

The solutions will include a full line of interoperable Serial Attached SCSI initiators, expanders and bridges - all the chip-level components needed to build Serial Attached SCSI systems - and Serial Attached SCSI RAID add-in cards to maximize data availability.

Serial Attached SCSI solutions also will support dual-ported disk drives, currently available only with Fibre Channel products, to deliver a level of fault tolerance previously not available at a midmarket price point.

back to top

< back