While installing an ATA may be the most straightforward way of getting a minimum installation up and running, it is not without its caveats. Consider the following:
- Most ATAs do not support pulse dialing. So, DTMF converters of some sort will be necessary in all but a few of the brands.
- A typical ATA is an FXS-only unit. This is great for calling out from your switch into the rest of the Collectors' Net. But, for incoming calls, all it can do is send ringing voltage.
- In homing off of someone else's Asterisk switch, you will be using the SIP protocol on all but one of the (currently) known ATAs. This will involve opening a range of ports through your firewall. This probably won't present much of a security hole, but could be tedious to configure.
All in all, though, it's much easier to get things going with an ATA than it is to put together an Asterisk switch. Additionally, there is plenty of expertise on the VoIP Mailng List if you have questions.
So, what are the considerations in choosing an ATA? Here is a handy chart to help you decide.
| Make and Model |
Rotary Dial Capable |
Number of FXS Ports |
Number of FXO Ports |
Transport Protocol |
Notes |
|---|---|---|---|---|---|
| Digium IAXy | Yes | 1 | - | IAX2 | Not exactly cheap for a 1-port ATA |
| Motorola VT1000 | Yes | 2 | - | SIP | Locked to Vonage ordinarily. Look for one on eBay that is unlocked. |
| Sipura 2000 | No | 2 | - | SIP | |
| Sipura 3000 | No | 1 | 1 | SIP |
So, how **do** you go about configuring one of these beasts once you have it? Here's the simple answer: Read the manual, and ask the person who will be hosting your ATA what settings you need but don't have the answers for. Typically, these would be:
- User Name
- Password
- Host Name