Softphone works through the VPN tunnel, established from the PC, and in most cases VPN software disables split tunnel (accessing a local resources when VPN connection established). So, you cannot connect an external device to utilize the VPN tunnel. Here are a couple ways you can use to connect an hardware phones at home:
1. Get a router with VPN capabilities (VPN connection should be established from the router, not the PC). This will allow to run PC and phone connection to the office. However there is a drawback - if you don't have split tunnel VPN, then ALL your home PCs will go to your work network, which may create a security breach...
2. Install a VoIP gateway in the DMZ. For example, get a Cisco router running CCME and SIP, and connect it at the office. Then you will be able to connect phones from home, but you have to plan your security very carefully.
3. Install Cisco's Phone Proxy. Basically it's the same thing like in solution #2, but designed specifically for IP telephony.
Good luck,
Mike
CCNP, CCDP, CCSP, CCVP, MCSE W2K, Security+, etc.
http://www.headsetadapter.com
http://www.ciscoheadsetadapter.com
