Despite Asterisk’s IP phone bias, outbound trunks do not have to be IP. Not only can Asterisk link with commercial VoIP providers such as BroadVoice and VoicePulse, but with the right hardware in place, it can also handle TDM circuits such as channelized T1s to deliver dial tone from the PSTN. Individual analog PSTN lines can also be brought into play with PCI line cards within the Asterisk server or via outboard FXO (foreign exchange office) ATAs such as the Grandstream GXW-4108, which can handle eight POTS lines, each addressable as a unique SIP trunk within Asterisk.
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Light on Linux requirements
Perhaps the most fundamental misconception about Asterisk is that it requires you to be a Linux shop. Not true. The open source PBX runs as a service on many platforms, including Windows, as there are projects available to enable Asterisk to run on 32-bit Windows.
Constructed much like your traditional PBX, Asterisk is based on a Unix-like OS hidden by a CLI or GUI management layer. You can deploy a standard Linux server and install the Asterisk package to create your own PBX or go with one of the several customized Linux distributions based around Asterisk.
Today’s most popular distribution is Trixbox, which consolidates a CentOS Linux platform, Asterisk, a bevy of open source Asterisk management tools, and custom code to make rollouts easier. With Trixbox, you can go from bare metal to a fully functional Asterisk IP PBX in 20 minutes. The same can be said for Digium’s recently released AsteriskONE, which takes a similar tack as Trixbox but offers different management tools.
In delineating differences between Trixbox and AsteriskONE, Spencer points out that, although Trixbox uses Asterisk, it is completely separate from Asterisk itself. “AsteriskONE is basically an HTML gateway between Asterisk and your Web browser,” he says. “If you make a manual change, it’s reflected in both Asterisk and the Web UI. Trixbox doesn’t have that.”
Trixbox does, however, offer significant features AsteriskONE lacks, such as easy implementation and configuration of the HUDLite user GUI, SugarCRM integration, and configuration tools for popular IP phone models. That said, AsteriskONE is still in beta.