Administrator Guide

462 Fabric OS Administrator’s Guide
53-1001763-02
Fibre Channel routing concepts
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To do so, at least one translate phantom domain is created in the backbone fabric. This
translate phantom domain represents the entire edge fabric. The shared physical devices in
the edge have corresponding proxy devices on the translate phantom domain.
Each edge fabric has one and only one xlate domain to the backbone fabric. The backbone
fabric device communicates with the proxy devices whenever it needs to contact the shared
physical devices in the edge. The FC-FC Routing Service receives the frames from the
backbone switches destined to the proxy devices, and redirects the frames to the actual
physical devices. When connected to edge fabrics, the translate phantom domain can never be
the principal switch of the backbone fabric. Front domains are not created; rather, only
translate phantom domains are created in the backbone fabric.
Devices are exported from the backbone fabric to one or more edge fabrics using LSANs. See
“LSAN zone configuration” on page 477 for more information.
NOTE
Management Server Platform services and interopmode are not supported in the backbone fabric.
Phantom domains
A phantom domain is a domain emulated by the Fibre Channel router. The FC router can emulate
two types of phantom domains: front phantom domains and translate phantom domains.
A front phantom domain is a domain that is projected from the FC router to the edge fabric. There is
one front phantom domain from each FC router to an edge fabric, regardless of the number of
EX_Ports connected from that router to the edge fabric. Another FC router connected to the same
edge fabric projects a different front phantom domain.
The second level of phantom domains is known as a translate phantom domain, also referred to as
translate domain or xlate domain. The translate phantom domain is a router virtual domain that
represents an entire fabric. Device connectivity can be achieved from one fabric to another—over
the backbone or edge fabric through this virtual domain—without merging the two fabrics. The
EX_Ports present translate phantom domains in edge fabrics as being topologically behind the
front domains; if the translate phantom domain is in a backbone fabric, then it is topologically
present behind the FC router because there is no front domain in a backbone fabric.
If an FC router is attached to an edge fabric using an EX_Port, it creates xlate domains in the fabric
corresponding to the imported edge fabrics with active LSANs defined. If you import devices into
the backbone fabric, then an xlate domain is created in the backbone device in addition to the one
in the edge fabric.
Figure 72 on page 463 shows a sample physical topology. This figure shows four FC routers in a
backbone fabric and four edge fabrics connected to the FC routers.