Brocade Fabric OS FCIP Administrator's Guide v7.1.0 (53-1002748-01, March 2013)

Fabric OS FCIP Administrator’s Guide 19

53-1002748-01

FCIP Trunking

- A limit of 10 FCIP circuits can be configured on a single 10 GbE port.

- A limit of 20 FCIP circuits can be configured per VE port group (12 through 21 or 22

through 31) when using a 10G port. For the 20 circuits, 10 are configured on local ports

and 10 on crossports

- For a FX8-24 blade with a VE_Port group on a 10GbE port, the sum of the maximum

committed rates of that group's circuits cannot exceed 10 Gbps.

NOTE

For any FCIP circuit going over the 10GbE ports, the back-end limit is rounded to the

nearest 1 Gbps increments for each VE_Port group. As an example, a circuit defined as 1.5

Gbps is actually going to consume 2 Gbps of back-end bandwidth. The maximum

aggregate amount is 10 Gbps total.

- For Adaptive Rate Limiting (ARL), you can configure a maximum rate of 10 Gbps for all

tunnels over a single 10 GbE port and 10 Gbps for any single circuit.

FCIP circuit failover capabilities

Each FCIP circuit is assigned a metric, either 0 or 1, which is used in managing failover from one

circuit to another. FCIP Trunking with metrics uses LLL, and no in flight data is lost during the

failover. If a circuit fails, FCIP Trunking first tries to retransmit any pending send traffic over another

lowest metric circuit. In Figure 5 on page 19, circuit 1 and circuit 2 are both lowest metric circuits.

Circuit 1 has failed, and transmission fails over to circuit 2, which has the same metric. Traffic that

was pending at the time of failure is retransmitted over circuit 2. In-order delivery is ensured by the

receiving 7800 switch.

FIGURE 5 Link loss and retransmission over peer lowest metric circuit

NOTE

Modifying a circuit metric disrupts traffic.

In Figure 6, circuit 1 is assigned a metric of 0, and circuit 2 is assigned a metric of 1. Both circuits

are in the same FCIP tunnel. In this case, circuit 2 is a standby that is not used unless there are no

lowest metric circuits available. If all lowest metric circuits fail, then the pending send traffic is

retransmitted over any available circuits with the higher metric. Failover between like metric circuits

or between different metric circuits is lossless.

7800

Circuit 1 - Metric 0 - Active

Circuit 2 - Metric 0 - Active

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