Posted on October 7, 2016 2:29 pm
 |  Asked by Tim Doyle
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I cannot choose to put a service-policy with output of packets, only input. This is on both a physical and vlan interface.

Is this a limitation with code or hardware? There is only “input” available on the command “service-policy type qos input <name>”.

I am running version 4.15.5M on TridentII chips (DCS-7050SX-64-F).


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Posted by Sergey Kolobov
Answered on October 19, 2016 3:14 pm

Hello Tim,

If I understand the purpose of this policy correct, for limiting bandwidth on the egress, you can have VLANs mapped to different traffic classes and configure traffic shaping on the Tx queues, but the number of VLANs is limited by the number of Tx queues/traffic classes. For this platform it is 8 and the top 2 already used for control plane traffic. You are probably already well aware, but just reminding that shaping comes with added latency owing to queueing.


Hope this helps.

Best regards,


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