Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
Community Member

Maintaining QOS for VOIP traffic with VPN running

In this scenario there is a need to roll out the phone systems over the Internet, this is mainly to remote teleworkers.

The phones are separate hardware devices to the PCs connected via a hub them into a Cisco 1720. These then connect to an Internet IP address. The PCs are also connecting to the corporate network via Symantec’s Raptor mobile client.

Even after trying various techniques to maintain the QOS for the voice traffic on the router, as per a number of Cisco technical documents, but have been unable to stop the inevitable break-up of the conversation as soon as the link is used for other traffic. provide some pointers as to whether this is possible (over ISDN) and some pointer as to which way to proceed.


Re: Maintaining QOS for VOIP traffic with VPN running

Voice over the internet VPN cannot

produce good quality because you can and only have controll over QOS in your existing device

interface and after the packets leave you router is would not be given any preference or higher priority over the internet.

They would inturn face delays, jitter etc which willd efinately result in bad quality voice.

VPN span various hops via the internet to the remote device, hence QOS can only be guranteed in environment where you have control.

The isdn link might be a better solution for both voice and data. This would be a direct dial-up 128KB bandwidht to the headquaters

and hence you have control of both router at the HQ and telecomter site.

Hence the right QOS an be applied and voice quality will be greately improved.

CreatePlease to create content