QoS for a Proprietary App

[Hawk]

I have 4 sites on an mpls network and 3 of the sites are congesting the main site wan circuit (mpls).  All sites only have 5meg circuits for site to site only traffic so it's not hard to congest but one of the offices is using the main site circuit to get to a VPN tunnel to access this app.  Since the main site circuit is always at 100% utilization packets are getting dropped to this app.  I set up IP sla to ping a server on the other side of the tunnel from the site that needs to get to this app and the stats are terrible.  They only initiate traffic to main site and there is an output policy on both routers but I'm not sure if or how I should add to it or if there is a better mechanism to use.  In summary I would like to give traffic destined to this app priority over other site to site traffic hitting the main site circuit.  How and what configuration should I use?  Please only experienced persons give suggestions.  This is not a certificate testing practice question.  Thanks.

[Georg Pauwen]

Hello,

a basic QoS policy would be fairly easy to implement. The exact syntax depends on the platform (e.g. ISR 4431) and the IOS version you are running. Do you know which TCP and/or UDP port the application uses ? If so, you can use those to classify the traffic, otherwise, use source and destination IP addresses. 

So in short, we need to see the configuration of your main site router, and some informatiion about the application traffic you want to prioritize...