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We have the following equipment for our internet and voip access

  • 2 x netgear ADSL routers
  • 1 x DHCP / DNS server (Windows 2008 server)
  • Numerous PCs
  • VOIP Phones

I want to configure our network so that data is routed over one of the ADSL lines and VOIP over the other.

How would we go about this? With or without purchasing additional hardware. (It doesn't matter)

Edit: To (hopefully) clarify things. We have a proposal from the IT guy for split ip ranges. Phones being assigned to one range which use the SDSL router and data assigned to the other range using the ADSL as default gateway. This just sounds wrong to me with my very limited networking experience and I'm sure that you can route based on destinated IP or Port but don't know wther I need a 'proper' router to do this

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What's acting as your voice switch? Do you DSL routers support QoS, if not your voice quality will suffer everytime someone is downloading anything. – Chopper3 May 4 '12 at 13:18
@Chopper3: As far as I have understood, this is exactly what this question is about: Separating data and voice traffic using two lines. – Oliver May 4 '12 at 13:33
up vote 2 down vote accepted

It depends on how your network is set up.

A very simple method would be to configure your PCs and your VoIP phones with different default gateways:

  • Router 1 is the default gateway for the PCs
  • Router 2 is the default gateway of the VoIP phones
share|improve this answer
this is what is currently being recommended by our IT guy. which means that we end up with either static ip addresses or dedicated network ports on the wall. which i wanted to avoid – Mark May 4 '12 at 13:44
You say that you have a Windows 2008 DHCP server: Just create a pool with the MAC addresses of your VoIP phones and a pool for all other, unknown addresses. – Oliver May 4 '12 at 13:49
so for the phones pool use SDSL as default gateway and vice-versa? – Mark May 4 '12 at 13:51
Yes, you got it. Requires no other hardware, just some configuration. And the best thing: if you miss a phone, it will still work, it's just the quality which might suffer. – Oliver May 4 '12 at 13:54
When I think of it, you might even be able to automatically recognize the phones on the DHCP server using the vendor-class-identifier or a similiar option. I don't know the Windows DHCP server good enough to tell you how exactly. – Oliver May 4 '12 at 13:57

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