A Multipoint Control Unit (MCU) is a device commonly used to bridge videoconferencing

Videoconferencing

Videoconferencing is the conduct of a videoconference by a set of telecommunication technologies which allow two or more locations to interact via two-way video and audio transmissions simultaneously...

 connections.

The Multipoint Control Unit is an endpoint on the LAN

Local area network

A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...

 that provides the capability for 3 or more terminals

Terminal (telecommunication)

In the context of telecommunications, a terminal is a device which is capable of communicating over a line. Examples of terminals are telephones, fax machines, and network devices - printers and workstations....

 and gateway

Gateway (telecommunications)

In telecommunications, the term gateway has the following meaning:*In a communications network, a network node equipped for interfacing with another network that uses different protocols....

s to participate in a multipoint

Multipoint

Multipoint may refer to:* Multi-point fuel injection, an injection scheme for metering fuel into an internal combustion engine* Multipoint ground, a type of electrical installation which involves the creation of many alternate paths for electrical energy to find its way back to ground* Multipoint...

 conference. The MCU consists of a mandatory Multipoint Controller (MC) and optional Multipoint Processors (MPs).

Common manufacturers

• Aethra
  Aethra
  In Greek mythology, Aethra or Aithra was a name applied to four different individuals:-Mother of Theseus:...
  
  
• Avistar
• Cisco TelePresence
  Cisco Telepresence
  Cisco TelePresence, first introduced in October 2006, is a product developed by Cisco Systems which provides high-definition 1080p video, spatial audio, and a setup designed to link two physically separated rooms so they resemble a single conference room even though the two rooms may be on opposite...
  
  /CTMS
• Emblaze-VCON
• LifeSize
  LifeSize
  LifeSize, a division of Logitech, is a video and audio communications company that provides high definition video conferencing endpoints and accessories, infrastructure products and a cloud-based video collaboration platform. LifeSize's worldwide headquarters is located in Austin, Texas...
  
  
• OpenMCU - an OpenSource Alternative for MCU (http://sourceforge.net/project/showfiles.php?group_id=80674), previously part of the OpenH323
  OpenH323
  The H323Plus project, formerly OpenH323, has as goal developing a full featured, open source implementation of the H.323 Voice over IP protocol. The code is written in C++ and, through the development effort of numerous people around the world, fully supports the H.323 protocol...
  
   Project, now in the H.323+ project http://www.h323plus.org/http://www.openh323.org/
• OpenVCS - an OpenSource MCU manager based on Doubango framework
• Polycom
  Polycom
  Polycom is a multinational corporation with approximately 3,200 employees worldwide and an annual revenue of approximately $1.2 billion in 2010. The company manufactures and sells telepresence and voice communications solutions.-Company History 1990:...
  
  
• Radvision Ltd.
  Radvision Ltd.
  RADVISION., founded in 1992, is a Nasdaq and Tel Aviv Stock Exchange-traded company, which is a component of the TA-100 Index of the largest 100 companies traded on the Tel Aviv Stock Exchange by market cap, it provides products and technologies for videoconferencing, video telephony, and the...
  
  
• Tandberg
  Tandberg
  This article is about the video-conferencing vendor, a Cisco company. Other companies with the same name such as Tandberg Television or Tandberg Data for data storage: see here and here...
  
  /Codian
  Codian
  Codian is a former supplier of video conferencing products. Since 2007, the company has been a part of Tandberg.Codian was founded in 2002 and based in Langley, Slough, UK. It was acquired by Tandberg in 2007 for USD 270 million. Codian's products – including their Multipoint Control Units...
  
  
• Avaya
  Avaya
  Avaya Inc. is a privately held computer networking, information technology and telecommunications company that is a global provider of business communications systems. The international head quarters is in Basking Ridge, New Jersey, United States...