Mbone

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Mbone (short for "multicast backbone") was an experimental backbone for IP Multicast traffic across the Internet developed in the early 1990s. It required specialized hardware and software. ^[1]Since most Internet routers have IP Multicast disabled due to concerns of bandwidth tracking and billing, the Mbone evolved to connect multicast-capable networks over the existing Internet infrastructure. The commercialization of multicast routers is difficult because there are no efficient access control capabilities to the multicast trees (multicast routers and their protocols), and because Internet service providers have difficulty computing charges for multicast traffic.^[1]

By 1995 there were M-bone links in Russia, as well as at the McMurdo Sound research station in Antarctica.^[1]

Mbone is currently of practical use for shared communication such as videoconferences or shared collaborative workspaces. It is not generally connected to Internet service providers, but often to universities and research institutions. Some other projects and network testbeds, such as Internet2's Abilene Network, have made Mbone obsolete.

A recent application with support over Mbone was Virtual Room Videoconferencing System (VRVS).

Details

• MBONE is a virtual network built on top of the Internet; Invented by Van Jacobson, Steve Deering and Stephen Casner in 1992.^[1] The purpose of MBONE is to minimize the amount of data required for multipoint audio / video-conferencing

• MBONE is free; it uses a network of mrouters that can support IP Multicast; enables access to real-time interactive multimedia on the Internet

• Many older routers do not support IP Multicast; to cope with this we must set up tunnels on both ends; also known as a tunneling protocol; multicast packets are encapsulated in unicast packets and sent through a tunnel;

• MBONE uses a small subset of the class D IP address space (224.0.0.0 - 239.255.255.255) assigned for multicast traffic. MBONE uses 224.2.0.0 for multimedia conferencing

• Characteristics:
  • topology: combination of mesh and star networks
  • IP addresses: 224.2.0.0; routing schemes: DVMRP, MOSPF
  • session registration: IGMP protocol
  • traffic requirement: audio 32-64 kbit/s, video 120 kbit/s

• MBONE tools:
  • Videoconferencing: vic -t ttl destination-host/port (supports: NV, H.261, CellB, MPEG, mJPEG)
  • Audioconferencing: vat -t ttl destination-host/port (supports: LPC, PCMU, DVI4, GSM)
  • Whiteboard: wb destination-host/port/ttl
  • session directory: sdr

References

1. ^ ^{a b c d} nytimes, 'Peering Out a 'Real Time' Window, Peter H. Lewis, 8 February 1995. Retrieved 26 Aug 2009.

See also

• Multicast
• CastGate - an attempt at providing connectivity to the multicast network for hosts which have none

External links

• MBONE: Multicasting Tomorrow's Internet: Classic book about MBONE, by Kevin Savetz, Neil Randall, and Yves Lepage, complete on-line
• How to connect to the MBone
• Site with Multicast Tester to see if web client host has access to Mbone
• Multicast Beacon Project
• http://www.accessgrid.org/
• What is MBONE? From Webopedia

Historical clients

• LBNL's tools
• MICE's tools
• OpenMash

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