SipX
Encyclopedia
sipXecs is an open source
voice over IP telephony server. Its main feature is a software implementation of the Session Initiation Protocol
(SIP), which makes it an IP based communications system (IP PBX). Featurewise, it is not unlike Asterisk
, a very popular open source PBX, but the design of sipXecs deviates from Asterisk in many ways. Development started in 1999, but in 2004 Pingtel Corp contributed the codebase to the non-profit organization SIPfoundry. It is an open source project since then. Pingtel assets were acquired by Nortel in 2008 and Nortel continued to support the project with several key enhancements and additions. Subsequent to the Avaya acquisition of Nortel in December 2009, Avaya has backed out of sipXecs and SIPfoundry. Former members of Pingtel and Nortel have create a new commercial entity call eZuce, Inc. (www.eZuce.com) to carry sipXecs forward and provide commercial versions of the software and support. Source code acquired by sipX is available under the Affero General Public License
(AGPL) as well as a commercial offering from eZuce Inc.
sipXecs includes many features of a traditional private branch exchange (PBX) like voice mail, interactive voice response systems, auto attendants and the like. Furthermore it integrates with Exchange 2007 and Active Directory Environments.
The main components of the system are designed around FreeSWITCH
a media router. In contrast to its main open source competitor Asterisk PBX
and most commercial offerings that use SIP as a transport protocol, SipX does not play the role of a back-to-back user agent. This approach led to a modular and highly scalable system. All major components of sipX are implemented as servers and do not necessarily have to reside on a single machine only.
sipXecs adheres to the SIP philosophy of implementing many features with significant support in the endpoints (telephones, gateways, voicemail systems) rather than entirely in the core components (proxy). This improves scalability but makes many features dependent on support in the endpoints of the telephone system.
and major Linux
distributions, including Red Hat Enterprise Linux
, Fedora Core
, CentOS
, Debian
and others. Beginning with version 3.10 sipXecs does have native support for PowerPC (big endian) systems. Currently the system is being built only for CentOS / Red Hat. Installation packages are available as well as modified ISO images of complete distributions with easy to use installation routines for sipX.
-attached SIP
hardware and also software phones. sipX itself does not interface to traditional phone lines. To attach ordinary (non-VoIP) phones or PSTN lines to the PBX, IP/PSTN gateways have to be used. sipXecs supports a number of commercially-available gateways.
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
voice over IP telephony server. Its main feature is a software implementation of the Session Initiation Protocol
Session Initiation Protocol
The Session Initiation Protocol is an IETF-defined signaling protocol widely used for controlling communication sessions such as voice and video calls over Internet Protocol . The protocol can be used for creating, modifying and terminating two-party or multiparty sessions...
(SIP), which makes it an IP based communications system (IP PBX). Featurewise, it is not unlike Asterisk
Asterisk (PBX)
Asterisk is a software implementation of a telephone private branch exchange ; it was created in 1999 by Mark Spencer of Digium. Like any PBX, it allows attached telephones to make calls to one another, and to connect to other telephone services including the public switched telephone network and...
, a very popular open source PBX, but the design of sipXecs deviates from Asterisk in many ways. Development started in 1999, but in 2004 Pingtel Corp contributed the codebase to the non-profit organization SIPfoundry. It is an open source project since then. Pingtel assets were acquired by Nortel in 2008 and Nortel continued to support the project with several key enhancements and additions. Subsequent to the Avaya acquisition of Nortel in December 2009, Avaya has backed out of sipXecs and SIPfoundry. Former members of Pingtel and Nortel have create a new commercial entity call eZuce, Inc. (www.eZuce.com) to carry sipXecs forward and provide commercial versions of the software and support. Source code acquired by sipX is available under the Affero General Public License
Affero General Public License
The Affero General Public License, often abbreviated as Affero GPL and AGPL , refers to two distinct, though historically related, free software licenses:...
(AGPL) as well as a commercial offering from eZuce Inc.
sipXecs includes many features of a traditional private branch exchange (PBX) like voice mail, interactive voice response systems, auto attendants and the like. Furthermore it integrates with Exchange 2007 and Active Directory Environments.
The main components of the system are designed around FreeSWITCH
Freeswitch
FreeSWITCH is a free and open source communications software for the creation of voice and messaging products. It is licensed under the Mozilla Public License , a free software license...
a media router. In contrast to its main open source competitor Asterisk PBX
Asterisk PBX
Asterisk is a software implementation of a telephone private branch exchange ; it was created in 1999 by Mark Spencer of Digium. Like any PBX, it allows attached telephones to make calls to one another, and to connect to other telephone services including the public switched telephone network and...
and most commercial offerings that use SIP as a transport protocol, SipX does not play the role of a back-to-back user agent. This approach led to a modular and highly scalable system. All major components of sipX are implemented as servers and do not necessarily have to reside on a single machine only.
Design philosophy
sipX is distinguished from most other open source VoIP PBXs by several characteristics:- All call signaling is handled using the SIP protocol natively (vs. gatewaying SIP to some other signaling protocol, e.g. as done in the Asterisk PBXAsterisk PBXAsterisk is a software implementation of a telephone private branch exchange ; it was created in 1999 by Mark Spencer of Digium. Like any PBX, it allows attached telephones to make calls to one another, and to connect to other telephone services including the public switched telephone network and...
). - The sipXecs components handle call signaling, but once a call is set up, the voice (media) packets are sent directly between the endpoints involved. This allows most of the sipX components to be agnostic about the media and its encodings. E.g., SIPSession Initiation ProtocolThe Session Initiation Protocol is an IETF-defined signaling protocol widely used for controlling communication sessions such as voice and video calls over Internet Protocol . The protocol can be used for creating, modifying and terminating two-party or multiparty sessions...
-based Videophones can communicate without increasing the load on the sipX system. - The architecture of the system is client-server based and non-monolithic; the sipX components (proxy, media server, etc.) communicate between each other via the SIP protocol and can be run on different hosts (or replaced with other SIP components).
- The system administrative interface is web-based (vs. a command-line interface) and named sipXconfig.
sipXecs adheres to the SIP philosophy of implementing many features with significant support in the endpoints (telephones, gateways, voicemail systems) rather than entirely in the core components (proxy). This improves scalability but makes many features dependent on support in the endpoints of the telephone system.
Applications
sipXecs is used by small and large enterprises ranging up to about 10,000 users. The largest publicly announced deployment is at Amazon.com using an installation serving over 5,000 users.Availability
sipXecs was available on multiple platforms like FreeBSDFreeBSD
FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...
and major Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
distributions, including Red Hat Enterprise Linux
Red Hat Enterprise Linux
Red Hat Enterprise Linux is a Linux-based operating system developed by Red Hat and targeted toward the commercial market. Red Hat Enterprise Linux is released in server versions for x86, x86-64, Itanium, PowerPC and IBM System z, and desktop versions for x86 and x86-64...
, Fedora Core
Fedora (operating system)
Fedora is a RPM-based, general purpose collection of software, including an operating system based on the Linux kernel, developed by the community-supported Fedora Project and sponsored by Red Hat...
, CentOS
CentOS
CentOS is a free operating system based on Red Hat Enterprise Linux . It exists to provide a free enterprise class computing platform and strives to maintain 100% binary compatibility with its upstream distribution...
, Debian
Debian
Debian is a computer operating system composed of software packages released as free and open source software primarily under the GNU General Public License along with other free software licenses. Debian GNU/Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential...
and others. Beginning with version 3.10 sipXecs does have native support for PowerPC (big endian) systems. Currently the system is being built only for CentOS / Red Hat. Installation packages are available as well as modified ISO images of complete distributions with easy to use installation routines for sipX.
Hardware
sipXecs supports the use of EthernetEthernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
-attached SIP
Session Initiation Protocol
The Session Initiation Protocol is an IETF-defined signaling protocol widely used for controlling communication sessions such as voice and video calls over Internet Protocol . The protocol can be used for creating, modifying and terminating two-party or multiparty sessions...
hardware and also software phones. sipX itself does not interface to traditional phone lines. To attach ordinary (non-VoIP) phones or PSTN lines to the PBX, IP/PSTN gateways have to be used. sipXecs supports a number of commercially-available gateways.
Side Notes
- In addition to the above mentioned, the sipXecs system serves as a reference implementation of the SIP standard. It is used at SIPIT interoperability events organized by the SIP ForumSIP ForumThe SIP Forum is a non-profit organization devoted to advancing the adoption of the Session Initiation Protocol , a signaling protocol for use in initiating, modifying, and terminating an interactive session among two or more users that involves multimedia elements such as voice, video, instant...
to test interoperability of SIP solutions from many different vendors. - An automated SIP interoperability portal based on sipX is provided for free. It is primarily used by SIP phone manufacturers for SIP compliance and advanced feature testing.