VoIP PBX: Private Branch Exchange
A PBX provides an organization with voice infrastructure.
It usually includes such features as an auto attendant, call transfer, call forwarding, hold, etc.
The things we expect when using an office phone system.
VoIP brings some interesting advantages to a PBX.
Many of the features in a PBX come easy with the SIP protocal.
Since the this protocal is used outside of a single office it
becomes relatively easy to distribute the geographic scope of your PBX around
While the focus of the industry is still on the question of, how to we connect VoIP and PSTN calls,
the more interesting issues relate to reduced cost, distibuted geographic scope and increased
flexability of service provision. For instance becomes much easier to incorporate a smarter voice interaction
auto attendent, voice mail through email, web based administration and interacton, etc.
Lots of other things also become possible.
A SIP/H323/PSTN PBX comes in three basic flavors, Open Source, Proprietary and Virtual.
Of course, like any good eatery, mixtures are the spice of life.
O3: The Open Source Enterprise Data Networking Magazine:
"The premier issue looks at reducing voice infrastructure costs with open source telephony solutions, a look at multilayer
switching support in Linux, an introduction to open source IDS, google hacks and much more..
O3 is distributed free of charge in Letter format
You are free to mirror and redistribute O3 magazine, provided it is distributed without modification"
Published by Splice Networks
Based in Athens, OH, USA
Asterisk: The Open Source Linux PBX:
"Asterisk is a complete PBX in software. It runs on Linux and provides all of the features you
would expect from a PBX and more. Asterisk does voice over IP in three protocols,
and can interoperate with almost all standards-based telephony equipment
using relatively inexpensive hardware." Note that IAXTel
enables IAX clients to connect with each other over the Inter-Asterisk eXchange. "
SIPfoundary: sipX Family of Projects - The SIP PBX for Linux:
"The sipX solution is an open source small/medium scale Enterprise SIP PBX complete with voice mail
and auto-attendant. Alternatively, sipX can be used as a high performance Enterprise toll-bypass SIP router.
It combines all common calling features, XML-based SIP call routing, voice mail and auto-attendant,
Web-based configuration, as well as integrated management and configuration of the PBX and attached
phones and gateways. sipX is a modular server based solution that runs on standard Linux. sipX does
not require any additional hardware as it interoperates with any SIP compliant gateway, phone or application."
"A system that well and truly integrates fixed and mobile telephony, IP phones,
PC softphones, cordless phones, mobile/cellular phones, digital phones and IP Gateways"
Based in Woburn, MA, USA
"OnDO PBX is a software-based IP-PBX that is compliant with the IETF Standard Protocol
Session Initiation Protocol (SIP). OnDO PBX not only inherits traditional
PBX's essential features but also brings the benefits of IP.
OnDO PBX can be utilized in a single office setting or multiple office locations,
and it offers flexibility and options for future expansion."
Also provides Voice Server, SIP Server, and IVR. Free Trial Downloads of some products.
Based in San Mateo, Californi, USA
Initially IP-One is only available to businesses in Quebec and Ontario.
"TELUS Hosts and Manages the IP Application Infrastructure and Service suite
in a highly redundant and secure environment and provides you all the benefits
of an IP telephony service in a simplified pricing model."
Based in Canada
"TelCentrex is an Internet-based virtual PBX solution for business users.
With TelCentrex, you have all the features and benefits of an office PBX without any
of the hardware. With telCentrex you are connected to your virtual PBX over
the internet. To get started, all you need is an IP telephone and a high-speed
Internet connection, such as ADSL, broadband or similar."
Support for H.323 / SIP / IAX Based in London, UK. Serving EU
"As an innovator and provider of Voice over Internet Protocol (VoIP) solutions since 1995,
VocalTec's equipment is commercially deployed in over 130 countries. Our packet tandem
switching solutions for international/national long distance services leverage our
unique RapidFlo™ routing engine, as well as our industry-leading SS7 capabilities.
Carrier-hosted solutions for VoIP VPN, IP Centrex/Hosted PBX, conferencing, global
call center and calling card services enable new revenue generation from enhanced
services. VocalTec also provides VoIP solutions over wireless infrastructure (VSAT/WLL)
to meet the needs of rural markets."
Based in Israel, Operating Globally.
Voicetronix: Powering Open Telephony:
"Voicetronix is one of the few CT (computer telephony) hardware vendors with Open Source drivers" Cards and a turnkey
are provided. Based in Adelaide SA, Australia
PingTel SIP PBX:
"It’s the first enterprise-grade IP PBX available in open source, and fully embraces the
Session Initiation Protocol (SIP) — the standard for integrated voice, video and data
communications — as well as other industry standards, including Java, Linux, XML and VoiceXML."
Based in Woburn, MA, USA
"MX250 & MX1200 Enterprise Media Exchange. Between them they scale from 5 to 1200 users without additional hardware.
They combine the functionality of a PBX, voice mail server, voice gateway, and internet gateway."
Based in Sunnyvale CA, USA