Brocade Fabric OS Administrator's Guide Supporting Fabric OS v6.3.0 (53-1001336-02, November 2009)
424 Fabric OS Administrator’s Guide
53-1001336-02
QoS: SID/DID traffic prioritization
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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 83.
NOTE
If there is a single low priority flow to a destination ID (DID) and several medium priority flows to that
same DID, then it is possible that the medium priority flows would have less bandwidth because they
have to share the medium priority VCs, whereas the low priority flow would have a separate VC.
License requirements for traffic prioritization
License requirements are different for 4 Gbps and 8 Gbps platforms:
• 4 Gbps platforms
Do not require a license: Brocade 4100, 4900, 5000, 7500, 7500E, 7600, and 48000.
You must manually enable QoS on 4 Gbpsps ports.
• 8 Gbps platforms
SID/DID traffic prioritization is a licensed feature for the 8 Gbps platforms: Brocade 300,
5100, 5300, 5410, 5424, 5460, 5470, 5480, 7800, 8000, DCX, DCX-4S, and Brocade
Encryption Switch.
An Adaptive Networking license must be installed on every 8 Gbps switch that is in the path
between a configured device pair.
When you install the Adaptive Networking license, QoS is automatically enabled on 8 Gbps
ports, except for long-distance 8 Gbps ports. For long-distance 8 Gbpsps ports, you must
manually enable QoS after you install the license.
Trunking considerations before you install the Adaptive Networking license
This section applies only to 8 Gbps ports that are not long-distance ports.
TABLE 83 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