I have a question about some voip/vpn configuration. I've got two sites that have 1760 routers with fxo/fxs cards that are going to be tieing the two phone systems together with a couple of voip trunks. These are secondary devices on the network with no data traffic or real LAN even, but addressed with a 2nd wan ip on the fa 0/0 port. The only traffic going through these routers is voice/voip.
My question is about this voip setup with vpn. First off, should I or shouldn't I, or even can I? If I configure a site-to-site vpn connection, will the voip traffic pass over that? How would I set up a VPN tunnel for only the fxo/fxs cards with no "LAN" behind it? Is there a need to have a vpn? Any benefits to sending the voip data across vpn, other than the obvious encryption of the "call"?
The thing is, I've only setup a VPN with Cisco a few couple of times, and once was from a pre-configured script I found and the other was from some software called SDM. I've only known about setting up VPN's for connecting the LAN behind router A to the LAN behind router B. This setup has NO LAN. The only interfaces are the fa 0/0 (getting static wan ip), and the fxo and fxs cards handling the voice. I have no clue on how to configure a site-to-site VPN for this, or if I even can, or if I should.
The next two replies will have my voip configuration as it sits on the bench in testing; I have both fa 0/0 interfaces connected to the local LAN just for a connection and testing, but each will later be getting it's own static WAN IP on the fa 0/0 interfaces: