Egress Port and Priority Rate Shaping
Rate shaping is a method of regulating traffic rate to ensure a certain level of network performance. The difference between policing and rate shaping is that policing drops the excess traffic. Shaping buffers the excess traffic and thus insures a uniform pattern of traffic egressing. Shaping is required when the nature of traffic is busty and needs to be smoothened.
Qumran supports configuring rate shaping per priority queue or per port.
Configuring port-based rate shaping
With Port based rate shaping, total traffic can be limited to the shape rate within the limits of port bandwidth. Qumran supports per-port rate shaping configuration within a range of 52kbps to 1000gbps
Refer to
Table 15-9 for shape rate granularity.
Note: Port based shaping is supported only on physical interfaces.
(config)#interface xe1
(config-if)#shape rate 200 mbps
(config-if)#exit
The general syntax is:
shape rate <1-1000000000> (kbps|mbps|gbps)
Configuring priority-based rate shaping
Priority based rate shaping ensures a traffic shaping per priority queue traffic. Priority based rate shaping is configured on the queuing class-map representing priority queue. Shaping can be configured in absolute value or in percentage of bandwidth. Qumran supports per-queue rate shaping configuration within a range of 469kbps to 483gbps.
Refer to
Table 15-10 for shape rate granularity.
The following example shows a sample configuration of priority based rate shaping:
(config)#policy-map type queuing default pq
(config-pmap-que-def)#class type queuing default q3
(config-pmap-c-que-def)#shape 10 mbps
(config-pmap-c-que-def)#exit
The general syntax is:
shape <1-483000000> (kbps|mbps|gbps) | percent <1-100>)
See
Chapter 12, Configuring Egress Queues on Ports for details about queuing property configuration.
Queue drop counters verification
Drop counters with drop reasons can be verified globally by using the command:
#show hardware-discard-counters
+----------------------------------+--------+--------+
| Registers | Core 0 | Core 1 |
+----------------------------------+--------+--------+
IQM_QUEUE_ENQ_DISCARDED_PACKET_COUNTER 1596100
Reason: VOQ_MX_QSZ_STATUS Y
EGQ_PQP_DISCARD_UNICAST_PACKET_COUNTER 59807
Reason: SRC_EQUAL_DEST_INT Y