Showing results for 
Search instead for 
Did you mean: 

cisco 6500 VSS QoS : priority queuing AND shaping ?


we have cisco switches 6500 in VSS mode, the sup we have is sup 720-10GB.

we run the 12.2(33)SXI6, I am working on QoS and I read in the following url :

which seems to be the right one about the QoS available on a 6500 in a LAN, that :

priority queuing and shaping is mutually exclusive.

is that really so ?

in fact that sentence is in the paragraph :

"Allocating Bandwidth Between Standard Transmit Queues"

and the exact text is :



Enter the shape keyword to configure SRR. Use of SRR prevents use of the strict priority queue.

To configure SRR, any CoS or DSCP values mapped to a strict-priority queue must be remapped to a standard queue



we have found that the Ethernet service plus board for 6500 support hierarchical QoS policies,

url :

but it is a WAN board, and cisco Q & A link about 6500 & VSS :

states :

"WAN Modules : currently not supported"

So is there a possiblity (new version, hardware, etc. ?) in which priority queuing is possible along with shaping ?

The reason we need it is that the security equipment that is just after the 6500 VSS is not line rate, so we need to shape
at a bandwidth in which the security equipment won't drop packets at random and within the traffic there is TOIP and videoconferencing
needing a priority queue.
Hierarchical  QoS policies would be ideal but it is still a dream and we would be pleased to shape individually every class except strict priority one,
to make sure the traffic remains below the dropping threshold of the security equipment.