Brocade Communications Systems 53-1001763-02, Administrator'S Manual

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Fabric OS Administrator’s Guide 403
53-1001763-02
QoS: SID/DID traffic prioritization
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Ingress rate limiting is available only on the following platforms: Brocade 300, 5100, 5300,
5410, 5424, 5450, 5460, 5470, 5480, 7800, 8000, VA-40FC, Brocade Encryption Switch,
Brocade DCX, or DCX-4S.
•
QoS traffic prioritization takes precedence over ingress rate limiting.
•
Ingress rate limiting is not enforced on trunked ports.
Virtual Fabrics considerations: If Virtual Fabrics is enabled, the rate limit configuration on a port is
on a per-logical switch basis. That is, if a port is configured to have a certain rate limit value, and
the port is then moved to a different logical switch, it would have no rate limit applied to it in the
new logical switch. If that same port is moved back to the original logical switch, it would have the
original rate limit take effect again.
Limiting traffic from a particular device
1. Connect to the switch and log in as admin.
2. Enter the portCfgQos
--
setratelimit command.
portcfgqos --setratelimit slot / port ratelimit
Example of setting the rate limit on slot 3, port 9 to 4000 Mbps
portcfgqos --setratelimit 3/9 4000
Disabling ingress rate limiting
1. Connect to the switch and log in as admin.
2. Enter the portCfgQos
--
resetratelimit command.
portcfgqos --resetratelimit slot / port
Example of disabling ingress rate limiting on slot 3, port 9
portcfgqos --resetratelimit 3/9
QoS: SID/DID traffic prioritization
SID/DID traffic prioritization allows you to categorize the traffic flow between a host and target as
having a high or low priority. For example, you could assign online transaction processing (OLTP) to
high priority and backup traffic to low priority.
All flows without QoS prioritization are considered medium priority.
High, medium, and low priority flows are allocated to different virtual channels (VCs). High priority
flows receive more VCs than medium priority flows, which receive more VCs than low priority flows.
The virtual channels are allocated as shown in
Table 85 .
TABLE 85 Virtual channels assigned to QoS priority
Priority Number of VCs VCs assigned
High priority 5 10, 11, 12, 13, 14
Medium priority 4 2, 3, 4, 5
Low priority 2 8, 9