Technical data

82 Fabric OS FCIP Administrator’s Guide

53-1002474-01

WAN performance analysis tools

The ipperf option

NOTE

The ipperf option is for FR4-18i blades. It does not work with 7800 switches and FX8-24 blades.

The ipperf 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.

The 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, but the general recommendation is to run ipperf only when there are no active tunnels on

the IP network. Data transferred across an active FCIP tunnel competes for the same network

bandwidth as the ipperf session, and ipperf is attempting to saturate a network to determine how

much usable bandwidth is available between the sites. Unless you have a method to quiesce all

storage traffic over an active FCIP tunnel during ipperf testing, you may experience undesirable

interactions.

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.

Because 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.