LLQ and CBWFQ Queuing, ingress or egress interface?

[Meddane]

When applying a policy map using the service-policy command, what is the recommendation about where to apply the policy-map? in the ingress (input) or egress (output)? and why?

[Georg Pauwen]

Hello,

on a very basic level (and I am sure somebody else can explain that more in detail), both LLQ and CBWFQ are mechanisms that affect transmit (tx) traffic, so the related service policy should be applied outbound. You tell the interface which packets should be transmitted first, that is, which packets leave the interface in the outbound direction first.

[pman]

Hi,

I Suggests you look at a similar question asked on this topic:

https://community.cisco.com/t5/telepresence-and-video/qos-ingress-or-egress/td-p/2369011

ingress

"you might validate what you're receiving, and based on what you "seeing" drop, mark, remark and/or rate limit the ingress traffic.  Generally on egress, you deal with possible congestion, so you might prioritize some traffic over other traffic but you also might mark, remark, drop, rate limit and/or shape."

egress

"you deal with possible congestion, so you might prioritize some traffic over other traffic but you also might mark, remark, drop, rate limit and/or shape."

"Congested part is WAN, you have limited bandwidth there, so you classify your traffic, give it proper markings and pass on to WAN"

[Meddane]

Thanks a lot @pman for your valuable contributions as always.

[Joseph W. Doherty]

That depends on what you want to accomplish, as for one consideration, ingress and egress policies share some commands, but not all.

Further, like ACLs, depending on what you're doing, often you want to do some things ASAP (to distribute processing load and/or eliminate traffic also ASAP).  However, also like ACLs, sometimes when you could use an ingress or egress policy for the same purpose, and one is more "efficient" then the other, you might place policies in such a way to minimize the number of interfaces you need to support that policy on.