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MQC on a VIP card


Cisco doc says that routing updates and keepalives do not use seprate queues in a VIP based architecture, but, go to the default-class queue??? that sounds very different that what i thought, would anyone know why?

Here is what the doc says:

Cisco 7500 series (with distributed QoS and VIPs) Places pak_priority traffic in the class-default class queue by default or in a specifically configured (separate) queue.

When queued to class-default, packets go to the tail end of the queue. The pak_priority flag is used to avoid dropping the high-priority packets.


Re: MQC on a VIP card


There are a lot of differences in the way QoS is implemented on the distributed platforms compared to the non-distributed platforms. I believe Cisco is in the process of improving the operational and semantic feature consistency across platforms.

I quote from the Cisco Press book "End to End QoS Network Design Quality of Service in LANs WANs and VPNs":

"As part of this effort, Cisco is consolidating and improving the QoS code bases of the distributed router architectures (such as the Cisco 7500 series of routers) and the nondistributed router families (such as the Cisco 7200 to 1700 series routers). This initiative is called Consistent QoS Behavior code and should remove most (if not all) of the traditional QoS idiosyncrasies between the distributed and nondistributed platforms."

So give it time and the QoS features will all start to look consistent.

Hope that helps - pls rate the post if it does.