New technology i just learned about! Its called PIPQ, and stands for PVC Interface Priority Queueing.
As the name implies, its a Queueing method, and its only for frame-relay.
It basically functions in the same way as a PQ scheme, in that it has 4 queues, high, medium, normal and low.
Where it differs is that instead of putting packets into each queue, you “put PVC’s” into each queue, or rather, you designate into which queue this specific PVC should belong to.
When packets are then ready to be moved from to the transmit ring, you dequeue based on high, medium, normal and low priority. And that means taking packets going to PVC’s in the high priority queue first, then medium etc.
Thats basically all there is to it. Very basic QoS, but QoS never the less.
Its really simple to configure, so lets try it out.
The scenario is that you have a multipoint interface, with three PVC’s configured. Two going to your business partners, while the third is a link to your datacenter. Business partner 1 is a very good partner, while partner 2 has been lacking in their appreciation for Cisco gear :).The datacenter one is critical to your business needs, so you want to make sure that one gets preferential treatment.
DLCI assignment:
102 – Business partner 1.
103 – Business partner 2.
104 – Data center link.
We want to assign them to the following queues:
104 – High.
102 – Medium.
103 – Low.
Step 1)
Create some map-classes to map the queue to each PVC:
Step 2)
Apply these classes to the individual PVC’s:
Step 3)
Enable PIPQ on the main interface:
Step 4)
Verify the priority on each PVC. Note that PVC’s in the normal queue wont show up in this command:
And finally:
And thats all there is to it. Cool huh?
Take Care!