I am just getting to know QoS (on routers) properly, and I have one dilemma to solve.
Let's say we have a QoS policy applied to the router's WAN interface, in outbound direction. This is some serial link, for instance. We marked the traffic, and gave it some bandwidth - let's say 50% of the link.
So, in the case of a congestion, the marked traffic should always get 50% of the BW.
the Q: what will happen if heavy traffic starts coming in from the WAN link i.e. in the inbound direction of that same interface? Will that outbound QoS policy matter at all? Does IOS know how to check the receiving traffic also, in order to maintain desired BW set in the QoS policy? I mean, that WAN traffic is coming at full speed in the very same interface (in which I tried to reserve some BW in the output direction) and my guess it doesn't care about my policy. It just hits hard on my router - or am I missing something?
The solution would be to enforce the similar QoS policy on the neighbor router, but I just can't do that. The configuration of the network is complicated and it would be a major pain setting up QoS on the other side of that WAN link.
Basically, I need to reserve some BW for video surveillance traffic, but at the same time not to overload the WAN link. The easy way is to do a one-way QoS and reserve the BW in the out direction on the WAN interface. But is it enough? What about the incoming traffic from the WAN?
Thanks a lot