2. ATAs

The Analog Telephone Adapter - Turning a Real Phone into a Batphone

The ATA is a device that connects an analog telephone (like you would plug into a conventional land line) into a VOIP telephone service. It talks to a computer network, and lets an old fashioned phone work with a VOIP service. An ATA is useful for the following reasons:

  • ATA's are often cheaper than IP Phones, especially if you already have an analog telephone on hand.
  • Even when you add in the price of the ATA, an analog telephone handset can still be cheaper than an IP Phone. Especially when you factor in the cost of IP phones for multiple users. Cordless systems with expandable handsets are considerably cheaper than Wifi-based IP phones or IP phones with multiple cordless handsets.
  • Once your home or office wiring has been disconnected from the local telephone company demarc, an ATA can be plugged in your telephone wiring and provide service to all of the telephone jacks. This means that you may not have to fool with running Ethernet cable to all of the rooms that you would like to have a telephone in. For details on how to do this, click here.
  • ATA's can vary significantly in price, depending on hardware and software features. A plain ATA may only have a single Ethernet jack, a single FXS port and support a single SIP account. A sophisticated ATA may have a built in network router (for connecting to the Internet), it may have multiple FXS ports serving as multiple telephone lines via multiple sip accounts, and it may even have an FXO port for connecting to an existing analog line, such as a land line.

One thing to keep in mind when shopping for an ATA is the difference between an FXO port and an FXS port. Unlike Ethernet, where most modern network switches can automatically talk to other devices you plug in, analog telephones make a distinction between a port for a telephone line, and the port for telephone handset. It's very easy to get them confused. Rather than dig into an explanation, your ATA definitely has at least one FXS port. It probably doesn't have an FXS port for plugging in an existing telephone line.

For the longest time, my favorite line of ATA is the OBi series from Obihai. OBi ATA's are very easy to set up and don't require much in terms of network configuration. The OBiTalk website also makes it possible to configure an OBi ATA remotely, which can come in handy for setting up batphones for your friends and family in far away places. Another great feature is the Circle of Trust that lets an OBi ATA call all another OBi ATA directly, for free. The Circle of Trust can also allow users of one OBi to make calls through another OBi. This comes in handy when you want to use a landline or sip account remotely.

With the ever-changing nature of Google Voice and the acquisition of Obi by Polycom have somewhat diminished the usefulness of the Obi line of ATA. I recently replaced my Obi 202 with a Grandstream ATA/router for use with my home setup. I may re-flash the old Obi to use it as a dedicated GV trunk in the future, but for now I am fine with SIP and PSTN dialing.