Is Router Needed For One Computer With VOIP?

If I have a cable broadband connection, do I need to purchase the router to use Vonage and access the internet at the same time?

[TELECOM Digest Editor's Note: In addition to the telephone adapter device needed to operate the VOIP phone, you need some sort of router/splitter device to use the internet at the same time. Otherwise you are stuck with plugging in the phone when you wish to use it, or plugging in the computer when you wish to surf the net. but not both at the same time. The router allows you do to both at one time; but depending on the type of VOIP service you get, many of the telephone adapters in fact are routers as well. Vonage is like that; the TA used includes a simple router in the same unit. Bring the cable in one side, send output to the telephone and the computer at the same time. PAT]