From Wikipedia, the free encyclopedia
Jump to: navigation, search
Privately held company
Industry Telecommunications
Founded 1999
Founder Mark Spencer
Headquarters 34°43′6.23″N 86°41′34.27″W / 34.7183972°N 86.6928528°W / 34.7183972; -86.6928528, Huntsville, Alabama, United States
Key people
Mark Spencer, Founder and Chief Technical Officer;
Danny Windham, Chief Executive Officer
Website www.digium.com

Digium, Inc. is a privately held communications technology company based in Huntsville, Alabama. Digium specializes in developing and manufacturing communications hardware and telephony software, most notably the open-source telephony platform Asterisk.


Digium was founded by Mark Spencer in 1999 as Linux Support Services,[1] offering technical support and development services to Linux users. While exhibiting the company at Linux Expo,[2] Spencer and Keith Morgan successfully experimented with receiving a telephone call via VoFR using a PC running Linux. Building on the idea of call processing with PCs, Spencer developed software named Asterisk to act as a telephone system for the startup company.[3] Asterisk was published as open source software, which gave others the freedom to use, change, and improve the software.

Initially, Asterisk solely used frame relay to send and receive calls, but its capabilities quickly expanded, while frame relay reached obsolescence. Independently of Linux Support Services or Asterisk, Jim Dixon had begun the Zapata Telephony project[4] to create computer-telephony interfaces that relied on the strength of a general-purpose CPU rather than specialized DSPs. When Spencer encountered the Zapata Telephony project (abbreviated to Zaptel), he and Dixon collaborated to merge the Zaptel Linux drivers with the Asterisk code. The Zaptel software project significantly expanded the utility of Asterisk, allowing Asterisk to use T1 interfaces.[5]

As interest in Asterisk grew, Linux Support Services began to focus more on supporting Asterisk and addressing the telecom market.[6] In 2001, the company changed its name to Digium[7] and began manufacturing and marketing its first telephony hardware interface card, the Wildcard X100P. The following year, Digium began marketing the Wildcard T400P and E400P, four-port T1 interface cards, which were Jim Dixon's "Tormenta 2 PCI" design.[8] Digium continued to expand and refine its line of telephony interface cards, which remains a significant portion of its business.

In the years following, Digium experienced strong growth[9] and received industry accolades for the disruptive effects of open source telephony.[10] "VoIP using an open-source solution, such as Asterisk, will generate more business than the entire Linux marketplace today,"[11] said Jon 'Maddog' Hall, the president of open-source organisation Linux International. In August 2006, Digium raised $13.8m in first-round from venture capital firm and JBoss investor Matrix Partners.[12]

Early in 2007, Danny Windham joined Digium as CEO, while founder Mark Spencer became Chairman and CTO.[13] Later in the year, Digium announced the acquisitions of Sokol & Associates[14] and Four Loop Technologies. Sokol & Associates were producers of Asterisk training and the AstriCon conference. Four Loop Technologies were makers of Switchvox, an Asterisk-based Unified Communications System marketed to small and medium-sized businesses. As 2007 came to a close, Digium moved to its current 60,000-square-foot (5,600 m2) headquarters[15] in Cummings Research Park. With the company's fast-paced growth, the move fueled speculation about Digium as a target for acquisition.[16]

A trademark conflict with the ZapTel Corporation (makers of calling cards) prompted the May 2008 renaming[17] of the Zaptel open source software to DAHDI, the Digium Asterisk Hardware Driver Interface.

In January 2009, an independent research firm reported that Open Source PBXs comprise 18% of the North American market for PBXs, surpassing traditional vendors Nortel, Cisco, and Avaya. The report further found that Digium's Asterisk is the most widely used Open Source PBX software, with more than 85% market share of the Open Source market.[18]

Digium announced its ISO 9001 certification[19] for product quality in April 2009.

In collaboration with Skype Limited, Digium released in August 2009 Skype for Asterisk, a closed-source software add-on that allows Asterisk to participate natively in the Skype calling network.[20] Previously, Skype had solely employed a direct, user-to-user calling model. The Skype for Asterisk software brought Asterisk's advanced dialplan, IVR, Least-cost routing, and Call center features to the Skype network, a significant milestone.[21]

In a joint effort with IBM, Digium released in October 2009 Asterisk for Smart Cube, a version of Asterisk that integrates with IBM's Smart Desk user interface.[22]

Products and services[edit]

Digium's products are grouped into two categories: business phone systems and custom telephony solutions.

The business phone system product line is a range of server appliances running Switchvox, a Unified Communications System powered by Asterisk. Custom telephony solutions comprise digital and analog interface cards, echo canceling and transcoding hardware, and open source Asterisk software, as the tools and materials with which custom telephony solutions may be constructed.


  • Asterisk, Digium's most well-known product, is an open-source PBX application which runs on commodity PC hardware.
  • Asterisk Business Edition is a commercial version of Asterisk that is sold by Digium. Digium claims it undergoes more testing than the open source version.[23]
  • Digium also produces and supports proprietary addons to Asterisk, such as Codec G.729, Fax for Asterisk, HPEC (High Performance Echo Canceller), the Cepstral Connector (text to speech), and the LumenVox Speech Engine (voice recognition).


PCI cards[edit]

Digium makes a range of analog and digital PCI and PCI Express cards designed to work with Asterisk.


Digium also manufactures a variety of appliances designed to simplify PBX installation, support, and maintenance, albeit at the possible cost of disabling some of the more advanced features of Asterisk. One series of the products involves the use of Switchvox, a GUI frontend to Asterisk.

External links[edit]


  1. ^ Chapman, Beth. "Alabama Corporate Records". Alabama Secretary of State. Retrieved April 8, 2009. 
  2. ^ Litt, Steve (June 1999). "Mark Spencer interview". Troubleshooting Professional Magazine. Retrieved April 8, 2009. 
  3. ^ Dal (April 8, 2005). "Interview with Mark Spencer". SineApps. Retrieved April 8, 2009. 
  4. ^ Dixon, Jim (January 5, 2005). "History of the Zapata Telephony Project". Jim van Meggelen. Retrieved April 8, 2009. 
  5. ^ Rodgers, Steve (October 21, 2005). "The Asterisk PBX as a Linked Repeater Controller, pg 2" (PDF). TIARA Technology. Retrieved April 8, 2009. [dead link]
  6. ^ Savarese, Janine (July 13, 2006). "Inc.com Names Mark Spencer of Digium to its '30 Under 30: America's Coolest Young Entrepreneurs' Feature". MRB. Retrieved April 8, 2009. 
  7. ^ Wintermeyer, Stefan (July 4, 2006). "New Mark Sencer Interview". Asterisk VoIP News. Retrieved April 8, 2009. 
  8. ^ Dixon, Jim (January 5, 2005). "History of the Zapata Telephony Project". Jim van Meggelen. Retrieved April 8, 2009. 
  9. ^ Meyerson, Bruce (September 20, 2005). "Voice over Internet market sees changes". USA Today. Retrieved 8 April 2009. 
  10. ^ Hardy, Quentin (April 10, 2006). "Dial D for Disruption". Forbes. Retrieved April 8, 2009. 
  11. ^ Marson, Ingrid (October 6, 2004). "Open-source VoIP 'will be bigger than Linux'". ZDNet. Retrieved April 8, 2009. 
  12. ^ Kraeuter, Chris (August 9, 2006). "Digium Gets Funding From Matrix". Forbes. Retrieved May 4, 2009. 
  13. ^ Asay, Matt (June 25, 2007). "The Open Source CEO: Danny Windham (Part 13)". CNet News: The Open Road. Retrieved April 8, 2009. 
  14. ^ Bauduin, Raphaël (October 2007). "Profoss – Interview of Kevin P. Fleming". Profoss. Archived from the original on March 11, 2009. Retrieved May 4, 2009. 
  15. ^ "Digium Unveils New Corporate Headquarters in Huntsville". Retrieved April 8, 2009. 
  16. ^ "Linux Magazine's Top 20 Companies to Watch in 2008". Linux Magazine. January 10, 2008. Retrieved April 8, 2009. 
  17. ^ Fleming, Kevin (May 19, 2008). "Zaptel project being renamed to DAHDI". Digium Blog. Retrieved April 8, 2009. 
  18. ^ Malone, John (January 28, 2009). "Open Source PBX is 18% of North America Market". No Jitter. Retrieved December 25, 2009. 
  19. ^ Kempke, Laura (April 27, 2009). "Digium Achieves ISO 9001 Certification for Product Quality". Digium. Retrieved December 20, 2009. 
  20. ^ Hoover, Lisa (Sep 1, 2009). "Skype for Asterisk Gives Small Businesses the Best of Both VoIP Worlds". OStatic. Retrieved Dec 9, 2009. 
  21. ^ Courtney, Jim (September 9, 2009). "The Skype for Asterisk Story – Significant Details". OStatic. Retrieved April 8, 2009. 
  22. ^ Kerner, Sean Michael (October 15, 2009). "IBM, Digium Team on Asterisk Phone System". InternetNews.com. Retrieved December 20, 2009. 
  23. ^ http://www.digium.com/en/products/software/abe.php?tab=overview Asterisk Business Edition overview