FW V06.XX/HAFM SW V08.02.00 HP StorageWorks SAN High Availability Planning Guide (AA-RS2DD-TE, July 2004)

Table Of Contents
Planning Considerations for Fibre Channel Topologies
122 SAN High Availability Planning Guide
iFCP, each connected SAN fabric is maintained separately from the others, while
the IP network provides connectivity, congestion control, error detection, and
error recovery. Figure 48 illustrates iFCP WAN extension.
Figure 48: iFCP WAN Extension
iSCSI Protocol
iSCSI is a TCP/IP-based protocol for establishing and managing connections
between IP-based storage devices, hosts, and clients. iSCSI operates on top of
TCP, moving block data (iSCSI packets) over an IP Ethernet network. This
protocol consolidates SANs into a single IP network for data and storage traffic,
using Ethernet (not Fibre Channel) for the SAN and IP for the WAN. iSCSI
requires equipping both server and storage systems with iSCSI components,
resulting in additional capital costs and higher server overhead associated with
TCP processing. Applications include storage access where performance is not
critical. Figure 49 illustrates iSCSI WAN extension.