An FXO adaptor/gateway interfacing to your PBX is required with the analogue line that would normally connect with the analogue phone and a VoIP Phone or VoIP Adaptor (the latter in combination with a standard analogue handset) installed at the employee's premises. The employee will need to have broadband and a router to make this work.

A fixed IP address is not required, you can configure the FXO gateway at the office to route to a VoIP extension registered to a VoIP provider (for example route to: XXXXX@voiptalk.org) or, you could route to an internal IP address if you have VPN between your office and the employee's premises (route to: XXXX@192.168.XXX.XXX). Our service supports NAT traversal so as long as you have configured the device appropriately you do not have to worry about STUN or port forwarding.