I'm trying to find the most cost effective VoIP solution for one of our small branch offices. This office will have no more than 3 peoples, but each person requires to have a PC and Cisco IP phone (voicemail, multiple line, direct inbound, pstn dial out and etc).
Building will provide ethernet hand-off for internet access (part of T1 I guess) so we are planning to create VPN connection between our data center and the local gateway.
As for the PSTN connection, 2 POTS will be provided by LEC. Gateway should be able to accomodate 4 Ports FXO module.
What would be the smallest but the best router can handle firewall/VPN/IP Voice/PSTN for the small office?
Thank you very much for your help in advance.