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Fabric OS Administrator’s Guide 461
53-1001763-02
Fibre Channel routing concepts
21
Proxy devices
An FC router achieves inter-fabric 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 FC router receives
these frames, translates them appropriately, 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 71 illustrates this concept.
FIGURE 71
MetaSAN with imported devices
Routing types
The FC-FC routing service provides two types of routing:
•
Edge-to-Edge
Occurs when devices in one edge fabric communicate with devices in another edge fabric
through one or more FC routers.
•
Backbone-to-Edge
Occurs when FC routers connect to a common fabric—known as a backbone fabric—through
E_Ports. A backbone fabric can be used as a transport fabric that interconnects edge fabrics.
FC routers also enable hosts and targets in edge fabrics to communicate with devices in the
backbone fabric, known as
backbone-to-edge routing . From the edge fabric's perspective, the
backbone fabric is just like any other edge fabric. For the edge fabric and backbone fabric
devices to communicate, the shared devices must be presented to each other's native fabric.
Host
Target
Fabric 1 Fabric 2
FC router
E_Port
E_Port
IFL
IFL
EX_Port
Proxy host
(imported device)
Proxy target
(imported device)