Fabric OS FCIP Administrators Guide v6.4.0 (53-1001766-01, November 2010)

Fabric OS FCIP Administrator’s Guide 11
53-1001766-01
FCIP trunking
2
FIGURE 4 FCIP tunnel and FCIP circuits
Design for redundancy and fault tolerance
Multiple FCIP tunnels can be defined between pairs of 7800 switches or FX8-24 blades, but doing
so defeats the concept of a multiple circuit FCIP tunnel. Defining two tunnels between a pair of
switches or blades is not as redundant or fault tolerant as having multiple circuits in one tunnel.
FCIP tunnel restrictions for FCP and FICON acceleration features
Multiple FCIP tunnels are not supported between pairs of 7800 switches or FX8-24 blades when
any of the FICON emulation/acceleration features or FCP acceleration features are enabled on the
tunnel unless TI Zones or LS/LF configurations are used to provide deterministic flows between the
switches. These features require deterministic FC Frame routing between all initiators and devices
over multiple tunnels. If there are non-controlled parallel (equal cost) tunnels between the same
SID/DID pairs, these features will fail when a command is routed through tunnel 1 and the
responses are returned through tunnel 2. Therefore multiple equal cost tunnels are not supported
between the switch pairs when emulation is enabled on any one or more tunnels without
controlling the routing of SID/DID pairs to individual tunnels using TI Zones or LS/LF
configurations.When load leveling across multiple circuits, the difference between the committed
rate of the slowest circuit in the FCIP Trunk and the faster should be no greater than a factor of 4
(i.e. a 100 Mbps and a 400 Mbps circuit is ok, a 10 Mbps and a 400 Mbps circuit is not ok). This
ensures that the entire bandwidth of the FCIP Trunk can be utilized. If a user configures circuits
with the committed rates that different by more than a factor of 4, the entire bandwidth of the FCIP
Trunk may not be fully utilized.
FCIP circuits
The following list describes FCIP circuit characteristics and usage.
A circuit can have a maximum commit rate of 1 Gbps.
Beginning with v6.4.0 the minimum committed rate allowed on a circuit is 10 Mbps. When
upgrading to v6.4.0 from an earlier version, if there is a circuit configured with a minimum
committed rate of less than 10 Mbps, the circuit will need to be updated to have a committed
rate of no less than 10 Mbps.