Consumer VoIP - Connection alternatives
All the "big name" Consumer VoIP offerings include the correct equipment you'll need to use the service in handy packages that you can purchase at your favorite electronics retailer. These bundles are intended for self-installation by non-technical consumers, so include hardware that in many cases is already configured - at least for "simple" set-ups that don't include multiple computers or routers.
In most cases the equipment is an FXS adapter, more commonly known as an Analog Telephone Adapter or ATA (Figure 2).
Figure 2: VoIP using ATA
An ATA is pretty much what it sounds like - a device that adapts or converts standard analog telephone equipment for use with VoIP. This means it will have one or more RJ11 (4 wire) telephone jacks to connect your analog phone stuff and an RJ45 (8 wire) Ethernet jack for connection to your LAN or broadband modem. ATAs allow any analog phone equipment to be used with VoIP service, including fax machines, answering machines and cordless phones. ATAs take care of both media and signaling VoIP duties, so must support the protocol(s) used by your ITSP.
In VoIP's early days, the ATA supplied was typically a Cisco ATA-186 since less expensive alternatives weren't easy to come by. But once the consumer networking product companies smelled the blood in the VoIP waters, they started pumping out products that have pushed the higher-priced alternatives aside.
A product that you're sure to be seeing a lot will be the Linksys PAP2 (pictured at left), an ATA that provides connection for two standard phones or phone devices that Verizon recently announced will be supplied to its VoiceWing customers.
According to the folks over at Voxilla, the PAP2 is actually a repackaged Sipura SPA-2000 (more details here). Even though Linksys is mum on the issue, this Sipura press release (PDF) says their technology has been licensed by Linksys for the PAP2, RT31P2 router with built-in 2 port ATA that I mentioned earlier and WRT54GP2, basically an 11g wireless version of the RT31P2. As I was writing this article, AT&T announced that they'll be bundling both Linksys VoIP routers with their CallVantage service.
Using an analog phone plus ATA isn't the only way that ITSPs let you connect. Most also support soft phones like XTen's X-PRO and X-Lite (pictured right), but may charge an additional monthly fee for their use. Soft phones require only a computer to run on (and a suitable headset or integrated microphone and speaker) and can be convenient for VoIP users on the go. There are even soft phones that run on PocketPCs, for an even more mobile VoIP solution.
Another point to consider is whether to get an ATA that includes an FXO interface. The FXO interface connects to your PSTN phone line and lets you use your phone with your normal telco connection. The feature is suggested if you aren't ready to take the VoIP plunge entirely and will be keeping your regular phone connection. If your VoIP service goes down, or if you'd just rather use your telco line for a call, the built-in FXS - FXO converter will keep you connected. Low-cost ATA's with FXO connectors aren't easy to come by, however, and you'll have to do your own set up, since none of the major ITSPs offer them as part of their bundles.
The ZyXEL P-2002L VoIP ATA with PSTN Lifeline automatically switches connected phones over to your normal telco connection when it is powered down or your VoIP service isn't available. It also lets you dial a prefix to use the PSTN connection even when VoIP is active and automatically route 911 calls to your normal telco line.