GRE Tunnels for voice and data

Unanswered Question
May 21st, 2007

Hi All,

I have a new requirement and as per the attached diagram I need to set up two gre tunnels to the same destination with two different throughput i.e. site A and Site B will have a tunnel with 768 Kbps for voice and 256 Kbps for data.

Lets say subnet x.x.x.x for voice and y.y.y.y for data.I need help in getting the best out of a 3640 running 12.0 and another 7200 vxr running 12.0(13). Please give some inputs.

Thanks in advance



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spremkumar Mon, 05/21/2007 - 20:27


If you are sure that you are not going to use more than 256K for voice then you can configure the same way you have posted out here and configure rate-limit on both the tunnels for the maximum allowed bandwidth so that they dont choke the whole bandwidth available over the main link..

For configuring rate-limit you can refer the below link ...


subra4u Wed, 05/23/2007 - 00:14

Hi Prem,

Thanks for the Immediate Response, We are planning to have Voice for 768 Kbps but as for as the tunnel goes it will be like a data packet between our own custom developed servers.

Thanks & Regards

mheusinger Wed, 05/23/2007 - 03:49


There are some possibilities for voip and data over tunnels.

1) IF the packets pre-tunnel are marked (DSCP, IP precedence) then the GRE headers will also get the same markings. You can then setup a policy on the physical interface towards the internet to prioritize voip.

2) You could use "qos pre-classify" on both routers - newer IOS required though afaik.

3) use one tunnel and a nested policy.

Why do you need two tunnels?

regards, Martin


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