Reference Guide

22 Fabric OS FCIP Administrator’s Guide

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QoS SID/DID priorities over an FCIP trunk

• QoS medium - The default value is 30 percent of the available bandwidth.

• QoS low - The default value is 20 percent of the available bandwidth.

For the 7800 switch and FX8-24 blade, you can modify the default values. Note that this only

changes the QoS priority distribution in the tunnel and does not reconfigure the fabric. For the

FR4-18i blade, there is no QoS distribution on the tunnel. Also, you cannot change the default

values.

Change the priority percentages on the 8 Gbps platforms using the optional Percentage tunnel

argument for the portcfg fciptunnel create and portcfg fciptunnel modify commands. When

configuring QoS percentages for each level, remember the following:

• The three values must equal 100 percent.

• A minimum of 10 percent is required for each level.

• QoS priority settings must be the same on each end of the tunnel.

NOTE

Priorities are enforced only when there is congestion on the network. If there is no congestion, all

traffic is handled at the same priority.

Following are some examples of setting QoS priority levels on VE_Port 12:

• The following command sets the QoS high priority to 60 percent.

portcfg fciptunnel 1/12 create --qos-high 60

• The following command sets the QoS medium priority to 30 percent.

portcfg fciptunnel 1/12 create --qos-medium 30

• The following command sets the QoS low priority to 10 percent.

portcfg fciptunnel 1/12 create --qos-low 10

For more information on using the portcfg fciptunnel command and optional tunnel arguments,

refer to the Fabric OS Command Reference Manual.

Figure 7 on page 23 illustrates the internal architecture of TCP connections that handle QoS

SID/DID-based Fibre Channel traffic prioritization. Note that this illustrates a tunnel containing a

single circuit only.