Open Source

Dialogic Open Source Initiatives and Unified Communications

Dialogic has a number of products, both software and hardware, that can be used within the open source communications market for unified communications applications.

Add Media Processing or Signaling Functions to Unified Communications Applications with the DiaStar® Server

The DiaStar® Server (DSS) has been developed as an open source project, sponsored by Dialogic. DSS creates a bridge between a number of open source communications projects and a variety of advanced technologies that are proprietary to Dialogic. The design of the DSS allows Asterisk and FreeSWITCH developers to continue to program UC applications in their native environment (DialPlan) and still get access to Dialogic technology, without having to know anything about Dialogic® APIs or the C language.

Programming is done by using the Woomera protocol, which abstracts many of the media and signaling tasks away from the Asterisk or FreeSWITCH server. The channel drivers implemented as Woomera clients for both Asterisk and FreeSWITCH provide access to DSS media and signaling resources. Due to the simplicity of the Woomera protocol, other Woomera clients can be created easily. A Python client has been created to demonstrate this ease of implementation.

More information on the DiaStar Server can be found at

Dialogic® Blue™ Telephony Boards and Other Dialogic® Products for Open Source

The entry-level Dialogic® Blue™ Telephony Board offering is a low-profile one-span telephony board with software echo cancellation. The other Dialogic Blue Telephony Boards in the series have hardware echo cancellation and are available in one-, two-, four-, and eight-port versions with a half-length form factor. The entry-level board is suitable for installations of up to 2 ports, while the other boards scale to eight or more spans per system.

Because Dialogic Blue Telephony Boards support Linux and most of the features required for communications applications, they can be used in many Asterisk environments. Since they support many standard APIs, Dialogic Blue Telephony Boards can be useful in developing UC applications.

Dialogic® Media Gateways

Dialogic® Media Gateways (DMG Gateways) allow an IP telephony server, such as Asterisk, to operate in native IP mode while providing PSTN and/or TDM PBX connectivity. Because the connectivity is totally transparent, no load is added to the IP telephony server's operation.

Since the DMG Gateways manage all the complexities of the PSTN connection, systems can be confidently installed anywhere in the world, whether they are interfacing with analog, T1, or E1 networks. No IP telephony server software changes are necessary. The external appliance gateway handles the PSTN connection for UC, while the server continues to operate in its native IP mode.

Dialogic® Diva® Media Boards

Dialogic® Diva® Media Boards are in worldwide use as part of Asterisk-based PBX systems. In an Asterisk-based solution, the Diva Media Boards offload most media processing tasks from the Asterisk server to the Diva hardware, resulting in more reliable and scalable implementations. The Diva Media Boards are supported via the Chan_capi channel driver.

The Chan_capi channel driver (formerly called chan_dialogicdiva) allows Diva Media Boards (analog, T1/E1, and ISDN BRI/PRI) to work transparently under Asterisk as a PSTN interface. The Chan_capi driver gives Asterisk developers easy access to advanced media and signaling functions for UC, which are not available with media boards from other vendors:

  • Enhanced Media Functions — Hardware-based fax, large conferences, echo cancelation (up to 256 ms), FoIP (T.38), DTMF clamping, pitch control, volume control via DTMF, noise suppression, automatic gain control, and others. See a live demo of a running Diva based system at
  • Call Control Enhancements — QSIG extensions supporting all major PBX, ISDN supplemental services (such as explicit call transfer), and call hold and retrieve. Conventional SS7 (ISUP for ANSI and ITU) and SIGTRAN signaling are also supported.

Learn More about the Dialogic® Products and Open Source Projects

DiaStar Server

Project DiaStar is an open source project sponsored by the Dialogic Inc. whose purpose is to create software that allows open source developers to access portions of the Dialogic® product portfolio and bring advanced communications technology to demanding open source markets.

The DiaStar Server (DSS) was developed by Project DiaStar, and acts as a multi-function peripheral that can be implemented as a media gateway, signaling gateway, or media server. Because it operates in a distributed client-server environment, DSS can provide many beneficial features for open source developers working on Asterisk or other open source implementations.

More details are available online.

Dialogic® Blue Telephony Boards

Dialogic® Blue™ Telephony Boards are efficient host-based call-processing boards for the open source market, and they scale from one to eight E1/T1 ports. Their main features are call transfer emulation, line interconnect, G.711 support, Automatic Gain Control (AGC), and echo cancellation.

More details are available online.

Dialogic® Media Gateways

Dialogic® Media Gateways allow an IP telephony server, such as Asterisk, to operate in IP mode while providing transparent PSTN connectivity without additional load on the server.

More details are available online.

Dialogic® Diva® Media Boards for Asterisk

Dialogic® Diva® Media Boards can be used directly within an open source Asterisk PBX to provide a native connection to the PSTN network. Diva Media Boards have onboard DSPs that deliver the media and signaling needed for high-density communications processing.

More details are available online.