Hello folks, i'm after some wisdom here. First i'll explain the current config.

Site A ( Head office )
ADSL connection with 2830, ip range 192.168.0.0, DHCP Server, Telephone system on the network.

Site B ( Remote Office )
ADSL Connection with 2830, ip range 192.168.1.0

Site to Site VPN link established between the two sites ( on different subnet as I believe you cant have them on the same subnet ).

I need to have the devices at site B to get an IP address from site A. So, ultimately, what I would like is to have them on the same subnet. IS this at all possible with the kit above? Site A has a small business server 2011 and an ip phone system. Its the ip telephones at Site B that need to get a dhcp ip address so they can talk to the telephone system at Site A.

Can anyone please help / advise on this config and provide any solutions? I've spent countless hours searching for solutions on the net and I am unsure where to turn next.

You can't have them on the same subnet, as otherwise how would devices know that they
need to use the gateway to reach the other device(s) rather than just plop their
datagrams out onto the LAN. That's how routing works - by knowing what is
local or remote by subnet differentiation.

But why can't the phones have a local IP address and just be told to use the
remote VoIP server as their SIP server?

HI there, thanks for the reply.

Yeah, that was my thoughts on them being on the same subnet.
I don't see a problem with them having a local ip address, as I can turn on dhcp on the local 2830. I would have to speak to the phone support people about the config of the phones with regards to telling the units to look for the remote voip server. I'll speak to them, see what they say. Have to admit, I don't do phone systems, so I don't know what can or cant be done.

Cheers