I do occasionally use the voice (not fax) port for modem connection. It seems to work OK for the low speed modems we use to program certain alarm control panels. I have no reason to use a high speed modem over Vonage. My Internet access while in the USA is cable modem service. We're having both cable modem and DSL installed in the condo in Brazil. That should keep me online during occasional outages from one or the other service provider.