From Wikipedia, the free encyclopedia

Mbone (short for "multicast backbone") is an experimental backbone for IP Multicast traffic across the Internet. Since most Internet routers do not yet support IP Multicast, the Mbone has evolved to connect multicast-capable networks over the existing Internet infrastructure. It is anticipated that the Mbone will eventually become obsolete as more routers understand and forward IP Multicast traffic, which is a standard feature in IPv6. Some major difficulties with the commercialization of multicast routers are the lack of efficient access control capabilities to the multicast trees (multicast routers and their protocols) as well as the difficulty for an ISP to compute charges for multicast traffic.

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

Contents 1 Details 2 External links 2.1 Historical clients 3 See also

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

• MBONE is free; it uses 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 avoid this we must set up tunnels on both ends; multicast packets are encapsulated in unicast packets and sent through a tunnel;

• MBONE uses a small subset of 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
  • IP addresses: 224.2.0.0; routing schemes: DVMRP, MOSPF
  • session registration: IGMP protocol
  • traffic requirement: audio 32-64 Kbps, video 120 Kbps

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

• 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/
• Videoconference support over Mbone. Note: end-client does not use Mbone, but VRVS infrastructure does.
• What is MBONE? From Webopedia

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

• Multicast