Routing
Routing

Are peak information rate (PIR) and committed information rate (CIR) supported at the queue level on MX Series devices?

by Juniper Employee on ‎01-27-2016 12:57 PM - edited on ‎09-22-2017 09:10 AM by Administrator Administrator (1,393 Views)

Question

Are peak information rate (PIR) and committed information rate (CIR) supported at the queue level on MX Series devices?

Answer

Support for PIR and CIR on MPCs

 On MX Series devices using MPCs, CIR and PIR are supported at the queue level with class-of-service (CoS) schedulers. Use three rates, transmit-rate, shaping-rate, and excess-rate, which can be configured simultaneously, and use the excess-priority statement with excess-rate to manage the bandwidth in the excess region between CIR and PIR, as follows:

 

  • excess-rate—Use to configure the percentage of excess bandwidth traffic that should go into the queue in the excess region.
  • shaping-rate—Use to configure the maximum bandwidth usage, which sets the PIR.
  • transmit-rate—Use to configure the minimum bandwidth allocated to a queue, which sets the CIR.
  • excess-priority—Use to configure the priority of excess traffic in a scheduler as low, medium-low, medium-high, or high.

Support for PIR and CIR on DPCs

On devices using enhanced queuing DPCs, CIR and PIR are not supported at the queue level. PIR on these devices is supported by using the rate-limit statement. You can achieve an effect similar to CIR and PIR at the queue level by combining tricolor policers with rate-limit and drop profiles. You use the tricolor policers to enforce the CIR and PIR, by configuring the drop profiles to drop the yellow packets (packet loss priority (PLP): medium-high) before the green packets (PLP: low).

 

You can create a strict-high priority queue running at the same time as several high priority queues on all of the DPCs (including those with enhanced queuing and those without enhanced queuing). However, you cannot do this on devices using IQ2 PICs.

 

For more information, see MX Series Interface Module Reference