Brocade Fabric OS FCIP Administrator's Guide v7.1.0 (53-1002748-01, March 2013)
32 Fabric OS FCIP Administrator’s Guide
53-1002748-01
Open Systems Tape Pipelining
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portcfg fciptunnel 17 create 192.168.0.91 192.168.0.81 50000 -x 0 -d c0 -i
-K12345678901234567890123456789012 -l
portcfg fcipcircuit 17 create 1 192.168.1.91 192.168.1.81 50000 -x 0
portcfg fcipcircuit 17 create 2 192.168.2.91 192.168.2.81 50000 -x 0
portcfg fcipcircuit 17 create 3 192.168.3.91 192.168.3.81 50000 -x 0
portcfg fcipcircuit 17 create 4 192.168.4.91 192.168.4.81 50000 -x 0
portcfg fcipcircuit 17 create 5 192.168.5.91 192.168.5.81 50000 -x 0
Open Systems Tape Pipelining
Open Systems Tape Pipelining (OSTP) can be used to enhance open systems SCSI tape write I/O
performance. When the FCIP link is the part of the network with the longest latency, OSTP can
provide accelerated speeds for tape read and write I/O over FCIP tunnels. To use OSTP, you must
enable both FCIP Fastwrite to enable Tape Pipelining.
OSTP accelerates SCSI read and write I/Os to sequential devices (such as tape drives) over FCIP,
which reduces the number of round-trip times needed to complete the I/O over the IP network and
speeds up the process.
Both sides of an FCIP tunnel must have matching configurations for these features to work. FCIP
Fastwrite and OSTP are enabled by turning them on during the tunnel configuration process. They
are enabled on a per-FCIP tunnel basis.
FCIP Fastwrite and OSTP configurations
The FCP features used in FCIP Fastwrite and OSTP require a deterministic FC Frame path between
initiators and targets when multiple tunnels exist. If there are non-controlled parallel (ECMP)
tunnels between the same SID/DID pairs, protocol optimization will fail when a command is routed
over one tunnel and the response is returned over a different tunnel. To help understand the
supported configurations, consider the configurations shown in Figure 8 and Figure 9 on page 33.
In both cases, there is no multiple ECMP paths. In Figure 8, there is a single tunnel with Fastwrite
and OSTP enabled. In Figure 9, there are multiple tunnels, but none of them create a multiple
ECMP.