I have had a Vonage phone hooked up for about 3 months now and I love it.
My only complaint has been the default Vonage set-up for homes. Now, I admit I am a geek, but I also suspect that the voice over IP market (VoIP) has more than its fair share of geeks for customers. In my case, Vonage came with a Cisso/Linksys RT31P2 router. This router has a WAN port, two phone ports, and four LAN ports. I have 4+ computers, 2 network printers, a wireless access point, and network attached storage (see previous posts). I also prefer a full firewall on the perimater. So here are the changes:
1) Get a two or three port RJ11 phone adapter for the back of the router. The two phone ports are for line 1 and line 2. We only need to pay for one line, but I have an adapter so I can plug in both my deskphone with speaker, and a wireless phone. Get a cordless phone that does NOT use the 2.4Ghz band (don't want that next to your 2.4Ghz 802.11g access point). Also get a cordless phone that lets you add handsets. We have two handsets with one in the living room.
2) Set-up your firewall to conntect to the internet. Set the interior LAN to use DHCP and to use a network other than the defualts (192.168.0.xxx or 192.168.1.xxx). For example, you could use 192.168.50.xxx for your main LAN. (note: not using the default networks is critical to do now, in case you ever want to use VPN or other technologies while travelling to connect back to your office. Too many hotels and other WLAN access places use the defualt networks and it will cause all kinds of trouble).
3) Set-up the Vonage router to get its "exterior" address via DHCP. Set the interior LAN to a different address than the interior LAN on your firewall and activate DHCP. To continue our example, we can set this LAN to 192.168.510xxx.
4) Connect a patch cord from an interior LAN port on your firewall/switch to the exterior or WAN port on your Vonage router and turn the Vonage router on. Check for dial tone on the phone.
5) You may need to adjust the ports open on your firewall to allow the Vonage traffic to flow.
Connect the rest of your devices. You may need to also adjust the security settings on the Vonage router (or even turn them off) if you have problems with devices connected to the vonage router accessing network storage, printers, etc. on the other network. The security settings are not really needed because both sides of the Vonage router are on the inside of your firewall.
Why do this?
1) The firewall is much more secure AND flexible than the security settings on the vonage router.
2) I have 8 switchports on the interior LAN plus for switch ports off the vonage router on a sub-LAN. I also have a wireless accesspoint set-up the same as the vonage router with 4 switch ports on a sub-lan. I use two of the eight on the interior LAN for the Vonage router and wireless AP, leaving 14 open ports for the rest of my equipment. Much better than the 4 that the vonage alone would have given me.
3) Better performance. The Firewall/Router has more memory, a faster processor, and less to do than the vonage router. Rather than spending much of its limited resources on VoIP functions, the exterior router switches traffic at level 2 and routes a level three much faster. As my network grows, I add switches, and move large data to network storage or printers, the current setup is faster and more robust.