If you're using a Linksys router with the RT31P2 Vonage adapter it will work fine. Linksys publishes the procedure on their knowledge base ID 358.
I am using the same system with no problems...essentially you "cascade" the routers...change the router IP to 192.168.15.2...disable DHCP...from your modem you connect to Internet port of the RT31P2...connect "ethernet (1) on the RT31P2 to your router (I connected to "4")
All this may sound confusing, at least it does to me, so your best bet is to check out the Linksys Knowledge base...even ask their tech help via e-mail...that's what I did and they were most helpful.
This system works great with no problems - good luck
ok i currently have a modem that goes to a router with 2 phone jacks for my vonage phone service and lan 1 out also goes into computer.
according to its setup disk my netgear wireless router wants to be the first router.
i am afraid this will gum up my vonage signal. is it ok to have the wireless router first? anyone with vonage and a wireless router out there who can advise? thanks - fj