Whereas commercial VoIP vendors typically supply their own phones, tying them to their IP PBXes for solid integration and providing phone setup, configuration, and maintenance as part of their packages, when it comes to deploying an open source VoIP solution such as Asterisk, it’s strictly a BYOP (bring your own phone) affair.

That said, a massive number of Asterisk-compatible phones are already available, from around $50 for a basic handset to $800 per device. Several 802.11 wireless phones currently on the market include support for multiple VoIP protocols, including SIP, MGCP (Media Gateway Control Protocol), and IAX (Inter-Asterisk eXchange).

Among the major IP phone vendors, Polycom has been working closely with Digium to ensure that its phones are fully Asterisk-compatible, according to Mark Spencer, founder of the Asterisk IP PBX project and chairman and CTO of Digium. Phones from Aastra, Grandstream Networks, Linksys, and Snom all ship with SIP support and can easily be integrated into an Asterisk deployment.

As for those phone manufacturers that sell their own IP PBXes, such as Cisco, Spencer’s comments are salient. “This illustrates the classic problem,” he says. “Asterisk is both competitive and complementary to their products.”

Whereas Cisco would prefer customers buy its complete VoIP package, its phones now support SIP so that they can also be sold a la carte. Despite some versions of the SIP firmware on its 7000-series phones having difficulty with various Asterisk functions, Cisco’s move toward SIP compatibility has gone reasonably well.

The downside, of course, is that most phones won’t have the server-side support found in commercial products. As such, setup and configuration may be more difficult, although not terribly so. Many models do, however, come equipped with plenty of enterprise-ready features, such as large LCDs and built-in 802.1q-compliant switches to reduce cabling and configuration. Polycom also sells a version of its conference-room speakerphone with full SIP compliance.