HP StorageWorks XPath OS 7.4.X Administrator Guide (AA-RVHDD-TE, February 2006)

XPath OS 7.4.x administrator guide 47
Figure 5 Edge SANs connected through a backbone fabric
Proxy devices
In an isolated SAN, the physical topology of the interconnections between nodes and switches is closely
modeled by the logical topology of the connections between PIDs; this is not so in a meta-SAN. With an
MP Router in a meta-SAN, a node is projected into the logical topology as a proxy device. This is a proxy
topology.
An MP Router achieves interfabric device connectivity by creating proxy devices (hosts and targets) in
attached fabrics that represent real devices in other fabrics. For example, a host in Fabric 1 can
communicate with a target in Fabric 2 as follows:
• A proxy target in Fabric 1 represents the real target in Fabric 2.
• Likewise, a proxy host in Fabric 2 represents the real host in Fabric 1.
The host discovers and sends Fibre Channel frames to the proxy target. The MP Router receives these
frames, translates them appropriately, and then delivers them to the destination fabric for delivery to the
target.
The target responds by sending frames to the proxy host. Hosts and targets are exported from the edge
SAN to which they are attached and, correspondingly, imported into the edge SAN reached through Fibre
Channel routing.
Figure 6 illustrates this concept.
= LSAN
Multiprotocol
Router
Multiprotocol
Router
11
Edge SAN 2Edge SAN 1
Backbone
Fabric