Video over IP systems are part of Video Communication and Networking. Video over IP systems use video codecs to reduce the video size and then transmits the video over Internet Protocol (IP) network using Real-Time Transport Protocol (RTP) to somebody who is looking for this video. Various forms of Video over IP technology are: Video Broadcast over IP, Videos on Demand (VOD), Videoconferencing over IP, streaming video, real-time audio/video sharing, etc.

Legacy video signals are based on analog technology. They are carried via expensive transmission circuits. We now, however, live in a digital world. Through advancements in digital video compression composite audio and video signals can now be carried over typical network circuits both on the LAN and across the WAN, and even over the Internet. Video over IP or IP Streaming Video are newer technologies that allow video signals to be captured, digitized, streamed and managed over IP networks.

Video over IP Technologies

  • Video Broadcast over IPVideo broadcasting over IP is a network-based one-way transmission of video file content. The endpoint is merely a passive viewer with no control over the session. Video broadcast can be either Unicast or Multicast from the server. Typical applications of “Video Broadcast over IP” are live video broadcast of classroom trainings/speeches, live TV to mobiles and IPTV, etc.
  • Video on Demand (VOD) over IP – Generally speaking, VOD allows a user to request on demand a streamed video stored on a server. This technology differs from broadcast video in that the user has the options to stop, start, fast-forward or rewind the video as the service is interactive. VOD also has another feature in that it is generally accompanied by usage data allowing viewing and billing of video services or video time. While VOD can be used for real-time viewing, it is generally used for stored video files. This technology is used for e-learning, training, marketing, entertainment, broadcasting, and other areas where the end user has needs to view the files based on their schedule and not the schedule of the video supplier.
  • Videoconferencing over IPVideoconferencing (VC) is a combination of full duplex audio and video transmissions which allows people in two different locations to see and hear each other as if participating in a face-to-face conversation. A camera is utilized at both endpoints to capture and send the video signals. Microphones are used at each endpoint to capture and transmit speech which is then played through speakers. The communications are real-time and generally not stored. These services can be used for applications including corporate communications, telemedicine, telehealth, training, e-learning, telecommuting and customer service. Videoconferencing can be point-to-point (one user to one user), or multipoint (multiple users participating in the same session). Users in the latter are viewed in separate windows.

Video over IP System Design Standards and Protocols

  • H.323 Protocol – H.323 is an ITU umbrella standard describing a family of protocols used to perform call control for multimedia communication on packet networks. Four major elements, namely, terminals, gateways, gatekeepers, and multi-point control units are defined in the H.323 standard and its addendums. The most important protocols used to set up, manage, and tear down calls are H.225 and H.245. H.225 is used to perform call control, and H.245 is used to perform call management.
  • Session Initiation Protocol (SIP) – Session Initiation Protocol (SIP) is an Internet Multimedia Architecture established by the Internet Engineering Task Force (IETF), SIP may be used for Voice over IP (VoIP), video conferencing, instant messaging, and is being planned for use in 3G wireless applications as well as new converged data and voice applications. It is an application layer signaling protocol used to establish, modify, and terminate multimedia sessions and is part of the. SIP applications include voice, video, gaming, instant messaging, presence, call control, etc. In the spirit of other Internet based applications, SIP relies on a number of other computer communications standards including Session Description Protocol (SDP), Real-Time Protocol (RTP), TCP, UDP, and so on.