Qos On E_Ports; Supported Configurations For Traffic Prioritization; Qos With E_Ports Enabled - HP A7533A - Brocade 4Gb SAN Switch Base Administrator's Manual

QoS on E_Ports

In addition to configuring the hosts and targets in a zone, you must also enable QoS on individual E_Ports
that might carry traffic between the given host and target pairs. Path selection between the host,target pairs
is governed by FSPF rules and is not affected by QoS priorities. By default, QoS is enabled on E_Ports in
port configuration. For example, in
H1
H2
= Low priority
= Medium priority
= High priority
= E_Ports with
QoS enabled
Figure 36

QoS with E_Ports enabled

You must enable QoS on the E_Ports on both ISLs between Domain 3 and Domain 4 because either path
might be selected to carry the traffic.
You do not need to enable QoS on the E_Ports on the ISLs between Domain 1 and Domain 2 and between
Domain 2 and Domain 3, because these are not the shortest paths between the hosts and the targets.
However, if the ISL between Domain 1 and Domain 3 is broken, the path through Domain 2 would be
used.
To guarantee traffic priority, enable QoS on all possible E_Ports. Alternatively, you could use a TI zone to
limit the E_Ports that carry the traffic between a host,target pair and enable QoS on only those E_Ports.
If QoS is not enabled on an E_Port, the traffic prioritization stops at that point. For example, in
you disabled QoS on E_Ports 3,12 and 3,13 then the traffic from H1 and H2 to S3 would be low priority
from the hosts to Domain 3, but would switch to the default (medium) priority from Domain 3 to the target
S3.

Supported configurations for traffic prioritization

Note the following configuration rules for traffic prioritization:
IMPORTANT:
an ISL for a switch running a firmware version earlier than 6.0.0, the frames are dropped.
• By default, all devices are assigned medium priority. To be assigned high or low priority, hosts and
targets must be connected to:
• 8/8 SAN Switch or 8/24 SAN Switch
• 8/40 SAN Switch
• 8/80 SAN Switch
• FC8-16, FC8-32, or FC8-48 port blade in the DC director
• To preserve the priority level across ISLs, the switches must be running Fabric OS 6.0.0b or later and
must be one of the following: 8/8 SAN Switch, 8/24 SAN Switch, 8/40 SAN Switch, 8/80 SAN
Switch, 4/32 SAN Switch, 4/32B SAN Swich, 4/64 SAN Switch, 400 Multi-protocol router, 4/256
SAN Director, or DC Director.
308 Optimizing fabric behavior
Figure
Domain 1
3
15
Domain 2
All switches in the fabric must be running Fabric OS 6.0.0b or later. If QoS traffic crosses
36, QoS should be enabled on the encircled E_Ports.
Domain 3
1 9
14
13
8
16
Domain 4
S1
S2
12
7
S3
Figure 36 if