HP AA979A - StorageWorks SAN Switch 2/8V, Administrator'S Manual, Page: 414 / 465

420 Configuring and monitoring FCIP tunneling
About the
Ipperf
option
The WAN tool
ipPerf
(referred to simply as “
ipPerf
” in this chapter) is an option of the Fabric OS
portCmd
command. This option allows you to specify the slot and port information for displaying
performance statistics for a pair of ports. For this basic configuration, you can specify the IP addresses of
the endpoints, target bandwidth for the path, and optional parameters such as the length of time to run the
test and statistic polling interval.
Only a single
ipperf
session can be active on an FCIP GbE port at any time. Each FCIP port supports a
single instance of the WAN tool-embedded client running in only sender or receiver mode. You can,
however, use multiple CLI sessions to invoke simultaneous
ipPerf
sessions on different FCIP ports.
Running WAN Tool Sessions with an FCIP tunnel online
ipPerf
sessions use different TCP ports than FCIP tunnels, so you can simultaneously run an
ipPerf
session between a pair of ports while an FCIP tunnel is online. You can, for example, revalidate the service
provider Service Level Agreement (SLA) without bringing the FCIP tunnel down.
NOTE: For uncommitted bandwidth, any data transferred across the active tunnel will compete for
the same network bandwidth as the
ipPerf
session. Unless you have a method to quiesce all
storage traffic over the FCIP tunnel during ipPerf testing, you might experience undesirable
interactions.
FCIP port bandwidth
Allocation of the FCIP GbE port bandwidth behaves exactly the same for
ipPerf
as for FCIP tunnels. If
bandwidth is allocated for FCIP tunnels, the
ipPerf
session uses the remaining bandwidth. Since
bandwidth is already reserved for the FCIP tunnels, the
ipPerf
session is not affected by any active FCIP
tunnel. If no bandwidth is reserved, the
ipPerf
session competes for a share of the uncommitted
bandwidth. Starting an
ipPerf
session has an impact on any active uncommitted bandwidth FCIP tunnels
just like adding a new FCIP tunnel would. For example:
• Adding a committed-rate
ipPerf
session reduces the total uncommitted bandwidth shared by all the
uncommitted bandwidth FCIP tunnels.
• Adding an uncommitted-bandwidth
ipPerf
session adds another flow competing for the shared
uncommitted bandwidth.
The CLI and configuration system ensures that any bandwidth allocation does not result in an over
commitment of the FCIP GbE port. An active FCIP tunnel cannot be forced to give up its committed buffer
and bandwidth resources. Therefore, to commit a specific bandwidth to the
ipPerf
session, you must have
an equivalent amount of spare capacity on the FCIP GbE port.