Linux has become more than just an alternative to Microsoft it has
become a religion. Everywhere you look you will find almost rabid
supporters of the Linux operating system. Dare I say that Linux supporters
have become more vocal, more fanatical, and more loyal than Macintosh
enthusiasts? While Macintosh developed a large following from the insanely
great past to todays think different, Linux enthusiasts have
grown exponentially in just a few years. In a short time, Linux has
garnered a respectable market share in applications such as Web servers,
DNS servers, file servers, and more. Even some research computers at the
National Aeronautics and Space Administration are utilizing Linux. All of
this attention to Linux made me wonder, What about Linux telephony?
Just where are the Linux telephony applications?
For several years, Ive heard various vendors claim that they
developed a Linux-based PBX. Picazo
(which was bought by Dialogic and then acquired by Telecor) was one such
company rumored to have a Linux-PBX product in development. A few years
ago when Picazo told me this, I was extremely excited and I pressed them
to demonstrate the product for me. Unfortunately, I got the runaround.
This was around the time Dialogic bought them, so perhaps this product was
killed during or soon after the acquisition. My hopes were dashed that we
would see a truly open telephony system.
A few years passed, and there were still no Linux-based PBX
announcements. I certainly expected that someone would announce a
Linux-based PBX, so I decided to investigate further. I found that there
are indeed some companies developing Linux telephony applications,
including Linux-based PBXs.
A SHOW OF SUPPORT
Bayonne
Bayonne is a
telecommunications application server of the GNU Project, offering a free,
scalable, media-independent software environment for development and
deployment of telephony solutions for use with current and next-generation
telephone networks. Bayonne permits the creation of telephony applications
that can be directly integrated with traditional scripting languages and
tools commonly found on free software platforms such as GNU/Linux. Bayonne
offers a wide degree of telephony hardware support and a modular
architecture through plug-ins. In the sixth release of Bayonne, the focus
is providing a free software platform for creating and deploying
next-generation XML integrated voice applications. Traditionally, such
systems have only either been available as limited proprietary software,
or only provided thru external hosting services. I should mention that
Pika Technologies, a telephony board manufacturer, supports the Linux
platform. In fact, the Pika Inline GT and Daytona cards operate with
Bayonne under GNU/Linux using the latest MonteCarlo API.
Quicknet
One of the first telephony board manufacturers to announce support for
the Linux operating system was Quicknet
Technologie. Quicknets Linux Special Edition family of VoIP
products supports open source Linux drivers. Most, if not all, of these
products are H.323 audio-compliant, and provide G.723.1, G.711, G.728,
G.729a/b, and TrueSpeech audio compression in the hardware. When used with
the MicroTelco Gateway software (sold separately), Quicknets Internet
LineJACK product turns your analog telephone line and your PC into a
single-line telephone gateway.
Dialogic And NMS
Although it isnt highly publicized, Dialogic (now Intel) does
support drivers for their boards on the Linux platform. Not to be outdone,
NMS Communications also has beta Linux drivers, including Natural Access
2001-1 Beta and Fusion 4.2 Beta 2. But I would remiss if I did not
mention the true pioneer and leader in developing Linux drivers for their
voice boards Aculab.
Aculab
I believe that Aculab was the first major telephony board manufacturer
to announce driver support for Linux back in March 1999. In addition,
Aculab has a product called Whirlwind which is a CT Server offered in UNIX
environments such as Sun SPARC Solaris and Linux, as well as Windows NT.
It supports S.100, S.200, S.300, H.100, and more, making applications
easily portable to various operating systems.
Brooktrout Technology
In September 1999, Brooktrout Technology announced support for the
Linux operating system on their TR114 Series intelligent fax and voice
boards. They now support the Vantage Series, RDSP Series, RTNI Series,
TRxStream Series, and Netaccess Series product families on Linux.
Brooktrout Technology will also support Linux with RealComm 100, its
communications server based on the ECTF S.100 Revision 2 specification.
VoiceTronix
A smaller company, VoiceTronix,
founded in 1995, is an Australian company committed to developing and
supplying low-cost computer telephony hardware to the open source
community. All of their telephony cards (4 port and 8 port analog versions
available) run under Linux, FreeBSD, and Windows NT/98/2000, and all of
their drivers are open source.
Vasic
One company offering a development tool to create telephony
applications is Vasic, with its
script-based application translator. Vasic supports several Aculab cards
and a few Dialogic cards as well. According to their Web site, the initial
development was done on MS Windows NT/2000, but they are currently
concentrating on extensive development on Vasic for Linux (codename:Vanux).
Certainly, you could create a Linux-based PBX by using this tool. In fact,
the company claims that telephony applications already written using Vasic
include directory-assisted dialing, knowledge-based routing, predictive
dialing, screenpop, TTS, speech recognition, one-number service, and more.
Asterisk
As my search continued, I stumbled upon a company called Asterisk.
According to their Web site, Asterisk is an open source PBX and general
telephony toolkit that runs on the Linux operating system. Asterisk
provides a set of APIs that essentially make it a type of middleware
between Internet and telephony channels like VoIP, voice over frame relay,
etc., and telephony and Internet applications like voice mail, phone
directories, call parking, and so forth. Asterisk supports a flexible and
extensible channel API, allowing any number of real hardware or software
interfaces. It is purported to support ISDN, PRI, T1, and POTS through an
Adtran Atlas. The Quicknet Internet PhoneJack and Quicknet Internet
LineJack are both supported. Plans to support Lucent-based Winmodems also
in the works. This product is not a turnkey out-of-the-box Linux-based
PBX, and its still under development, but it does have several
telephony functions working, such as call bridging, call transfer, call
parking, and rudimentary voice mail. Check them out.
TeleData Technology
I discovered that TeleData
Technology manufacturers a Linux-based voice messaging system. While
it still is not a Linux-based PBX, it does have some interesting
functionality, including unified messaging, a Web-based message retrieval
interface, speech recognition, desktop call control, wireless, VoiceXML,
and SIP. Since I knew their product had all the hardware and much of the
software necessary to create a fully fledged Linux-based PBX, I asked if
they had plans to add PBX functionality to their system. They responded
that they could add this functionality quite easily but had no plans to do
so. Oh well, I guess my search continues.
eOn Communications
Then it hit me. I recalled that one of the TMC Labs engineers granted eOn
Communications a TMC Labs Innovation Award in 2000, and I remembered
that it ran on Linux. A check of their Web site confirmed a Linux-based
PBX that includes unified messaging, wireless, and CTI technology as well
as software for multimedia contact centers that includes Web chat, ACD,
e-mail routing, and call recording functionality.
OTHER COMPANIES
There is so much Linux development going on in the telephony field, I
cannot give an in-depth analysis of each company, but heres what else
is going on:
- Franklin Telecom: Franklin Telecom
offers a VoIP gateway based on Linux.
- Linux Telephony: Devoted
to news and information on Linux telephony. I like this site because
it has a lot of information as well as an online forum for posting
questions and reviewing answers to prior postings.
- OpenGatekeeper Project:
OpenGatekeeper is an open source H.323 gatekeeper based on the work by
the OpenH323 project. It runs on Linux, FreeBSD, and Win32 platforms.
- OpenH.323 Project: The
OpenH323 project aspires to create a full featured, interoperable,
open source implementation of the ITU H.323 teleconferencing protocol
that can be used by developers and end users without charge.
- OpenPhone: A site dedicated
to the development of high-quality, low-density Internet telephony
solutions for as many computer platforms as possible.
- Open Source Telecom: A Silicon
Valley start-up founded to provide commercial development and support
of open source telecommunications software. In addition to a full
range of consulting, development, porting, and testing services, OST
offers a powerful line of products based on Pika hardware. OSTs IVR
Server, the first open-source interactive voice response system,
combines PIKA hardware, Debian GNU/Linux, and the ACS communications
engine to deliver Web-enabled performance and flexibility in an IVR
system.
- OpenSS7.org: An open source
development project to provide a robust and GPLed SS7 stack for
Linux and other UNIX operating systems.
- OpenTelecom: Devoted to
open source software for computer telephony, specifically focusing on
hot-swap and circuit-switching capabilities for systems built with
CompactPCI and the H.110 CT bus.
- Vovida.org: A communications
community site dedicated to providing a forum for open source software
used in datacom and telecom environments.
- Voxilla: This site hosts open
source telecom software. It is a generally useful resource for those
who need to implement telecom applications on GNU/Linux.
Say, would you like to have a SIP or H.323 client on Linux? Hey, who
wouldnt? For a SIP client, check out http://simon.morlat.free.fr.
For an H.323 client, check out www.gnomemeeting.org,
which emulates many of NetMeetings features, including the ability to
connect to ILS servers and video functionality.
SEEING PROGRESS
While I have seen only one turnkey Linux-based PBX, I am pleased with
the work being done in Linux telephony. Utilizing Linux for your telephony
applications certainly has its advantages. It supports customized
applications, is extremely crash-proof, and has lower hardware
requirements than some other operating systems. In fact, Linux has an
extremely low entry cost, although the total cost of ownership (TCO) may
vary depending on the application. Just as Linux has lowered the entry
point for providers of applications for the Internet, it is poised to do
the same for telecommunications. n
[ Return
To The November 2001 Table Of Contents ]
|
