HP StorageWorks MSA 2.8 SAN Switch - Manual (Page 17)

Remote Switch
17 HP StorageWorks Remote Switch Version 3.1.x/4.1.x User Guide
Using Remote Switch
You can configure switches for use with Remote Switch using either telnet
commands or using Advanced Web Tools. For information about using Advanced
Web Tools to configure a switch, refer to the HP StorageWorks Web Tools Version
3.1.x/4.1.x User Guide.
Overview
The Remote Switch feature operates in conjunction with a Fibre Channel to FCIP
WAN gateway. This gateway provides both a Fibre Channel physical interface
functioning as an E_Port and an FCIP WAN physical interface.
The gateway accepts Fibre Channel frames from one side of a Remote Switch
fabric, transfers them across a WAN using an FCIP protocol, and passes them to
the other side of the Remote Switch fabric.
To transfer frames across a WAN using an FCIP protocol, the Fibre Channel
frames (from 256 to 2112 bytes) must be broken into pieces at the local end of the
FCIP network. Once they are broken into smaller pieces, they are tunnelled and
then transmitted across the network. At the remote end of the FCIP network, these
pieces are reassembled back into complete Fibre Channel frames and transmitted
through the remote Fibre Channel interface.
To accomplish this, the gateway provides an E_Port interface that links to the
SAN Switch E_Port. Once the link between the two E_Ports is negotiated, the
gateway E_Port moves to pass-through mode and passes Fibre Channel traffic
from the SAN Switch E_Port to the FCIP network.