Where should we configure Qos for VoIP phone or video traffic ?

[eigrpy]

Hi In a campus network, there are VoIP phone and video traffic, where should we configure the OoS? I think the Qos should be configured at the device where the traffic are considered as bottleneck, do you think so ? If so, usually it is at edge router, right ? Thank you

[Chris Deren]

QoS should be configured End to End, you should mark as close as possible to source (switch port) and queue and prioritize throughout the network. 

Check out Cisco's medianet QoS SRND:

http://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND_40/QoSCampus_40.html

[eigrpy]

Thank you so much for your reply. So we mark traffic as close as source, but we should set LLQ etc in bottleneck device, right ?  

[Chris Deren · Accepted solution]

LLQ is set on WAN links, which is the biggest bottleneck on any network, however before even getting there switching infrastructure needs to be properly setup for QoS with marking/classification and queueing.  Different switches have different QoS/queue capabilities and one needs to understand entire network (models of switches, supervisors, etc) to design compatible QoS structure end to end.

[eigrpy]

Thank you! very good explanation.

[Chris Deren]

You're welcome and good luck.

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