User guide

VIA or AMD Geode processors, these platforms have their limitations in terms of computational power
and cost.
In May 2007, I discovered the Free Telephony Project
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, a project started by David Rowe in Australia
that provides free reference designs for embedded telephony. The project has released a PBX known
as the IP04. The IP04 is an open (free as in speech) four port IP-PBX that can be built in volume for
around $100 and currently retails for around $400. Both the hardware and software are open which
means that anyone is welcome to manufacture, sell, modify and improve the design. It has been
developed by a community of telephony and DSP professionals, for community rather than business
reasons.
Image 5: Embedded PBXs. Linksys WRT, Mini-ITX, IP04.
The IP04 is based on the Blackfin BF532 chip - a powerful, low cost DSP/RISC processor that can
perform digital signal processing (DSP) and it runs uClinux. It is approximately 10 times as powerful as
the popular Linksys WRT54G when used for Asterisk. During the summer of 2007, We could test one
of the first units and see that is possible to integrate high quality echo cancellation and codecs on a low
cost embedded system.
The IP04 includes four sockets that support any combination of FXS or FXO modules. Apart from the
low cost and open nature of the project, the system is specially suitable for developing regions as runs
on low power (5W). One of the breakthroughs is the inclusion of OSLEC, an open, patent free echo
canceller.
32. http://www.rowetel.com/ucasterisk/index.html
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