Traffic Priority on WAN link

[VenkataRamana29848]

Dear All

We are using  Data, Audio, and Video  traffic In our cisco 2911 routers network.

WAN link is connected with serial interfaces of Routers

.

Our requirement is when all three types of traffics are available at input, only one type of traffic to be allowed through WAN link, and remaining other traffics to be blocked totally as per the priority list  given below.  

1st priority is Data

2nd priority is Audio

3rd priority is Video

If Data, Voice , and  Video traffic is available at input based  on priority only Data to be passed through WAN link and Voice and Video to be blocked.

If only Voice and Video is available at input then only audio to be passed through, and video to be blocked.

Kindly requesting all, please support me on this regard.

[Joseph W. Doherty]

At least to me, it's not 100% clear exactly what you want to happen, because of issue like what you exactly mean by "available at input" and how long to block.

If you mean such traffic waiting to be transmitted and data has absolute priority over audio and video, and audio also has absolute priority over video, in the past that could be accomplished by router priority queuing (not to be confused with switch PQ or CBWFQ class LLQ), but I recall (?) that feature is no longer supported.  If your 2911 has a recent IOS that supports two level LLQ, that, I think, might accomplish similar behavior, for just 3 classes (which is all you need).

It would be a CBWFQ policy something like:

policy-map recentIOS
class data
priority level 1
class audio
priority level 2

In older IOS versions, a CBWFQ policy something like:

policy-map notasrecentIOS
class data
priority percent 100 !not certain you can define 100
class audio
bandwidth remaining percent 99

Would be close to what you ask, but audio and video would split bandwidth 99:1, i.e. video wouldn't be totally blocked (BTW, that's possibly one reason "old" router PQ has been dropped, and perhaps why [and if] LLQ cannot obtain 100%).

BTW, placing data with absolute priority over audio and video is a good way to "kill" both.

[VenkataRamana29848]

Thank you very much for your response Sir,

Let me explain more..

We have two routers connected  with seral WAN link. 

DATA ( Laptop), Audio (Phone), and Video (Phone) are connected to LAN switch ports of each Router. 

Data/Audio/Video-----LAN- Router1---- S0/0/0 WAN---- Router2 -LAN----Data/Audio/Video

We need to allow only one traffic at a time instead of all three types of traffic to be passed simultaneously through WAN link. 

If all three Traffics are available at WAN link we need to block two and allow one as per priority.

I hope it gives more clarity, 

Requesting you to please do the needful.

With regards,

Ramana

[Joseph W. Doherty]

What I've previously posted will (more or less) do what you asked for.

[VenkataRamana29848]

Dear Sir,

As suggested below is the configuration I have Done in both the routers, 

class-map match-any Data
match qos-group 1
class-map match-any Video
match qos-group 3
class-map match-any Audio
match qos-group 2
!
policy-map R&D
class Data
priority level 1
class Audio
priority level 2
class Video
!
interface Serial0/2/0
service-policy output R&D

Then I have verified voice and  Data Transfer simultaneously, But I couldn't get the required result. observed same results without priority and with priority please.

Is there any other additional configuration to do, please suggest.

Regards,

Ramana

[Georg Pauwen]

Hello,

what are you matching in the qos groups ? Try to match on DSCP, this would look like below. 

class-map match-any Video
match dscp af41 cs4
class-map match-any Audio
match dscp ef cs3
!
policy-map R&D
class Audio
priority level 2
class Video
fair-queue
class class-default
priority level 1
!
interface Serial0/2/0
service-policy output R&D

[Joseph W. Doherty]

Your policy doesn't need a class "Video" as class-default can serve that purpose, which is always present even if not explicitly defined.

As already mentioned by @Georg Pauwen, why matching using QoS groups (which I recall [?] require setting up with an ingress policy).  As also described by Georg, match on ToS (and/or ACLs).

[VenkataRamana29848]

Thanks allot to all,

I will try to match on DSCP in our Test setup, and revert back.

Actually my requirement is to give top priority to Data Transfer, then Audio next Video. Since there is a limited bandwidth, and we require Data file to transfer immediately by using total bandwidth with out delay.

Thanks and Regards,

Ramana

[Joseph W. Doherty]

"Actually my requirement is to give top priority to Data Transfer, then Audio next Video."

Policy provided should do that.

That said, you might be disappointed by the "results".

Audio and/or video often can be totally broken if they don't receive sufficient bandwidth.  (Your requested policy is the generally opposite of what's normally done.)

The provided policy will FIFO your data (class), and not further manage flow drops.  For "typical" data streams, this can make for highly variable flow throughputs, often with a "goodput" less than optimal.