Fcip Circuit Failover Capabilities; Bandwidth Calculation During Failover - Brocade Communications Systems Brocade 8/12c User Manual

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FCIP trunking
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FCIP circuit failover capabilities

Each FCIP circuit is assigned a metric, which is used in managing failover for FC traffic. Typically,
the metric will be either 0 or 1. If a circuit fails, FCIP Trunking tries first to retransmit any pending
send traffic over another lowest metric circuit. In
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 8 Gbps Extension Switch.
FIGURE 283
In Figure
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,
FIGURE 284

Bandwidth calculation during failover

The bandwidth of higher metric circuits is not calculated as available bandwidth on an FCIP tunnel
until all lowest metric circuits have failed. For example, assume the following:
636
In a scenario where a FCIP tunnel has multiple circuits of different metrics the data will flow
over the lower metric circuits unless a failover condition occurs, as described in
failover capabilities".
The maximum bandwidth for a single circuit is 1 Gbps. However, a maximum of 10 Gbps per
circuit is allowed between 10 GbE ports on 8 Gbps Extension Blades when both blades are
running Fabric OS 7.0 or greater.
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Link loss and retransmission over peer lowest metric circuit
284, circuit 1 is assigned a metric of 0, and circuit 2 is assigned a metric of 1. In this
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Failover to a higher metric standby circuit
Figure 283, circuit 1 and circuit 2 are both lowest
Circuit 1
X
Circuit 2
Circuit 1 - Metric 0 - Active
Circuit 2 - Metric 1 - Standby
"FCIP circuit
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3 ? 1
Resend 2
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