When you sign up for VOIP service, your VOIP company will likely want to sell you a VOIP router as part of package. This isn't a bad thing. You're going to need a VOIP router or adapter that works with the service you chose. And you can often get a good deal if you buy directly from the VOIP service. But you are not required to buy a VOIP router from the provider. You can buy one from an electronics store, or EBay. The important thing to remember is to get a router that will work with the particular service you have chosen.