Fcip Fastwrite And Ostp Configurations - Brocade Communications Systems 8 Administrator's Manual

TABLE 12
FCIP Fastwrite
Class 3 traffic is accelerated with Fastwrite.

FCIP Fastwrite and OSTP configurations

To help understand the supported configurations, consider the configurations shown in the two
figures below. In both cases, there are no multiple equal-cost paths. In the first figure, there is a
single tunnel with Fastwrite and OSTP enabled. In the second figure, there are multiple tunnels, but
none of them create a multiple equal-cost path.
FIGURE 16
Fabric OS FCIP Administrator's Guide
53-1001766-01
Using FCIP Fastwrite and OSTP (Continued)
Single tunnel, Fastwrite and OSTP enabled
Options for enhancing tape I/O performance
OSTP
Class 3 traffic is accelerated between host and
sequential device.
With sequential devices (tape drives), there are 1024
initiator-tape (IT) pairs per GbE port, but 2048
initiator-tape-LUN (ITL) pairs per GbE port. The ITL pairs
are shared among the IT pairs. For example:
Two ITL pairs for each IT pair as long as the target has
two LUNs.
If a target has 32 LUNs, 32 ITL pairs for IT pairs. In this
case, only 64 IT pairs are associated with ITL pairs.
The rest of the IT pairs are not associated to any ITL
pairs, so no OSTP is performed for those pairs. By
default, only Fastwrite-based acceleration is performed
on the unassociated pairs.
Does not support multiple non-equal-cost path
between host and sequential device
Connection can be
VE-VE or VEX-VE
3
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