Gigabit Ethernet Switches
Gigabit Ethernet switches provide layer 2 link switching and layer 3 IP routing.
Gigabit Ethernet switch products range from 8 to more than 200 ports.
Port density is achieved through small form factor transceivers and RJ-45 connectors.
A Gigabit Ethernet switch can support multiple transmission speeds.
Cut-through switching routes packets based on destination address.
Store-and-forward switching buffers the entire packet before routing.
10Gbps interswitch links enable scalable, high-performance core networks.
Gigabit Ethernet switches support both IEEE and IETF standards.
Gigabit Ethernet directors can be used to build highly available data center SANs.
IP Routers
An IP router supports both Ethernet and wide area connectivity.
WAN links can include Packet over SONET, ATM, ISDN, frame relay, and point-to-point.
WAN link speeds range from T1 (1.544Mbps) to OC-192c (10Gbps).
IP storage traffic appears as standard IP packets to an IP router.
IP routers can incorporate QoS and IP security functionality.
iSCSI Adapter Cards
iSCSI can be implemented in software or offloaded in silicon to a Gigabit Ethernet NIC.
iSCSI adapters require TCP off-load engines (TOEs) to minimize host CPU utilization.
Pricing for iSCSI adapters is midway between standard Gigabit Ethernet NICs and Fibre Channel HBAs.
iSCSI adapters are changing the composition of SANs from predominantly Fibre Channel to predominantly IP.
iSCSI Storage Devices
The functionality provided by storage arrays and tapes is not changed by substitution of iSCSI for Fibre Channel at the interconnection.
iSCSI interfaces on storage targets provide flexibility in deployment of storage assets.
JBODs will probably remain SCSI or Fibre Channel-attached.
iSCSI-enabled storage is suitable for both data center and low-end storage applications.
IP Storage Gateways
IP storage gateways can provide Fibre Channel-to-iSCSI or Fibre Channel-to-iFCP protocol conversion.
IP storage gateway architecture can employ fixed ports for Fibre Channel or Gigabit Ethernet or multiservice ports that support both.
IP storage gateways provide E_Port connectivity to existing Fibre Channel fabrics.
iSCSI may not be suited to data replication between Fibre Channel storage arrays.
iFCP gateways provide protection against Fibre Channel fabric reconvergence issues.
iSCSI-to-SCSI Bridges
iSCSI-to-SCSI bridges enable legacy SCSI tape and disk to be integrated into an IP SAN.
Bridge products can include extended copy agents to facilitate server-free tape backup.
iSCSI-to-SCSI bridges extend the useful life of SCSI assets by leveraging them for new SAN-enabled storage applications.
iSNS Servers
iSNS servers allow centralized discovery, zoning, and security for IP SANs.
iSNS server products can be third-party devices in the IP network or can be integrated into more comprehensive storage management frameworks.