Scaling of Per-VLAN Queuing on Non-Queuing MPCs

To enable logical interface scheduling, you include the per-unit-scheduler statement at the [edit interfaces interface name] hierarchy level. When per-unit schedulers are enabled, you can define dedicated schedulers for logical interfaces by including the scheduler-map statement at the [edit class-of-service interfaces interface name unit logical unit number] hierarchy level. Alternatively, you can include the scheduler-map statement at the [edit class-of-service traffic-control-profiles traffic control profile name] hierarchy level and then include the output-traffic-control-profile statement at the [edit class-of-service interfaces interface name unit logical unit number] hierarchy level.

Table 2 shows the number of VLANs per port available in both 8-queue and 4-queue mode for 16x10GE, MPC3E, MPC4E and MPC6E.

Enabling and configuring per-unit schedulers on these interfaces adds additional output to the show interfaces interface name [detail | extensive] command. This additional output lists the maximum resources available and the number of configured resources for schedulers. Following is sample output showing the CoS scheduler resource information on a non-queuing line card:

root@R1# run show interfaces et-2/2/0 detail 

Physical interface: et-2/2/0, Enabled, Physical link is Down
  Interface index: 165, SNMP ifIndex: 550, Generation: 168
  Link-level type: Ethernet, MTU: 1522, Speed: 100Gbps, BPDU Error: None, Loopback: Disabled, Source filtering: Disabled,
  Flow control: Enabled
  Device flags   : Present Running Down
  Interface flags: Hardware-Down SNMP-Traps Internal: 0x4000
  Link flags     : Scheduler
  CoS queues     : 8 supported, 8 maximum usable queues
  Schedulers     : 0
  Hold-times     : Up 0 ms, Down 0 ms
  Current address: 80:71:1f:10:e6:b4, Hardware address: 80:71:1f:10:e6:b4
  Last flapped   : 2013-05-07 16:17:01 PDT (03:16:41 ago)
  Statistics last cleared: Never
  Traffic statistics:
   Input  bytes  :                    0                    0 bps
   Output bytes  :                    0                    0 bps
   Input  packets:                    0                    0 pps
   Output packets:                    0                    0 pps
   IPv6 transit statistics:
    Input  bytes  :                   0
    Output bytes  :                   0
    Input  packets:                   0
    Output packets:                   0
  Egress queues: 8 supported, 4 in use
  CoS scheduler resource information:
    Maximum units supported per MIC/PIC: 20
    Configured units per MIC/PIC: 1
    Maximum units allowed per port: 20
    Configured units on this port: 1
  Queue counters:       Queued packets  Transmitted packets      Dropped packets
    0 best-effort                    0                    0                    0
    1 expedited-fo                   0                    0                    0
    2 assured-forw                   0                    0                    0
    3 network-cont                   0                    0                    0
  Queue number:         Mapped forwarding classes
    0                   best-effort

If you enable more VLANs than the previously mentioned MPC/MIC combinations support, VLANs up to the supported numbers receive dedicated queuing resources. The additional VLANs share port queues. Scheduling for port queues cannot be controlled. However, port queues are guaranteed 1 percent of the physical interface bandwidth to avoid queue starving and buffer holdup.

In the case of MPC2E-NG/3E-NG, MPC5E and MPC7E/8E/9E SKUs, the following command needs to be configured to enable “flexible queuing” on the MPC. Configuration of this knob results in a reboot of the MPC. The per-unit-scheduler, hierarchical scheduling and 2 level hierarchical scheduling are supported. There are 32K queues enabled and they can be used for either ingress queueing or egress queueing. The 32K queues are available when all 8 queues are used per IFL.

chassis {  
     fpc 0 { 
         flexible-queuing-mode;        }
            }

Table 3 shows the number of VLANs per port available in both 8-queue and 4-queue mode for MPC3E-NG/MPC2E-NG, and MPC5E.