Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
As the others have noted, you can, for example using PBR, but it raises the complexity, especially if you need to deal with fail-over scenarios using PBR.
Personally, I prefer using QoS to insure service levels for VoIP, regardless of path. I've also had success with VoIP over Internet connections, like cable or DSL, the trick being managing bandwidth on the connection to/from the ISP. Although ISPs generally won't support QoS across the "Internet", usually congestion doesn't occur there first.
