Need to purchase an ATA or other piece of VoIP hardware?  There are plenty of retailers around.  Canadians may wish to use Shopbot.ca to find the best price at a Canadian retailer.  Americans may use Froogle or similar.  Does a deal sound too good to be true?  Maybe it is.  Be sure to check the retailer out on a site such as ResellerRatings.com.  If you don't feel like buying from a particular retailer, reputable retailers such as Netlink Computers/NCIX will often price match in stock items from other online retailers.  If you don't require a new unit, you can often find VoIP hardware on Craigslist.  Be sure to test these items before purchasing.  Sometimes, hardware is locked to a specific provider.  Unfortunately, there are a great deal of counterfeit VoIP devices on eBay (many from Asia) and via 3rd-party sellers on Amazon.  We suggest not buying from overseas and ensuring that your seller has a return policy.

For some information about how to detect counterfeit VoIP hardware, check out this post at DSLReports.com.


An Analog Telephone Adapter allows you to use your existing telephones or PBX system with a VoIP provider.  It's often the least expensive way to convert to VoIP.  Some VoIP providers require you to Bring Your Own Device (BYOD) while with others, the Device Is Supplied by the COmpany (DISCO).

If the ATA is supplied to you by the provider, you typically need not worry about configuring it as that will be done for you.  If the provider you choose requires you to BYOD, you will need to select and learn how to use an ATA.

There are two common manufacturers of ATAs.  The first we will mention is Grandstream.  Grandstream is known for making very inexpensive VoIP hardware.  We have heard reports of mixed success with Grandstream equipment.  Some have not been happy while some have no trouble at all.  VoIP Tech Chat Member PX Eliezer states that there is a significant issue regarding a feature of the Grandstream Handytone 286.  There is an option called Dial Plan Prefix String that can be selected which causes the unit to place a "1" at the start of any number you dial. That of course allows you to skip dialing the "1" yourself.  PX Eliezer urges you not to use this option because then you will not be able to call 911. If you dialed 911, the adapter would send it out as 1911, and you'd be in trouble.  So, if you have a 286, leave that box blank!

The most popular manufacturer of ATAs is Cisco.  Cisco makes ATAs formerly made by Sipura.  A company called Linksys bought Sipura, and then Cisco bought Linksys.  Cisco's adapters are the most popular due to their wide range of configuration options, their reputation for reliability, and their low price.  The feature that arguably most sets Cisco ATAs apart from Grandstream is the dial plan.  This very powerful feature allows you to customize dialing rules so that they properly match your region.  You may also customize practically everything else about your adapter to your heart's content, from ringing, to the busy signal, and even the dial tone.  Here, we outline the most popular Cisco ATAs currently in production and the differences between them:

PAP2T

This is the least expensive of Cisco's ATAs and by far the most popular.  It is an excellent choice for someone wanting to save some money and invest a little time rolling their own phone system, or even a VoIP veteran.  The PAP2T handles up to two providers on two separate lines.  That is, in order to use a second provider, you must have a second phone, or a 2-line phone.  The PAP2T does not support T.38 for faxing.  This means that while it is theoretically possible to send or receive a fax with a PAP2T, it will be slow and will not be reliable.

SPA2102

The SPA2102 is a PAP2T with a few extra features.  It supports T.38, so it will be much more reliable than a PAP2T for faxing.  The SPA2102 has a built-in router, but not a particularly good one.  Its QoS routing works for some users, however it's not particularly configurable and if it doesn't work for you there's very little you can do to fix it.  If you don't have a router that supports Quality of Service to prioritize VoIP, the best, most popular, and often cheapest option is any router with Tomato firmware installed on it.  A good QoS router is very important so that regular internet traffic does not degrade the quality of your VoIP calls.  With QoS, you can make VoIP calls with audo quality indistinguishable from (or better than!) POTS.

SPA3102

The SPA3102 handles multiple providers in different ways from the PAP2T and the SPA2102.  It only has one line so you can only make/receive one call at a time, but you can use the same phone and route the call through any provider you like using its gateway feature.  It does have an FXO port for connecting a POTS line.  The thought behind this feature was that you could call its POTS line from some other location and route your call inexpensively out over VoIP.  Or, you could route local calls through the POTS line and long distance through VoIP.  Unfortunately, the FXO port does not work nearly as well as many users hoped.  Most report poor audio quality including echoing.  The SPA3102 supports T.38 and contains a similar router to the SPA2102.

You may also want to consider an IP phone.  While IP phones typically involve a larger financial investment than an ATA, they often have more/better features.