MBONE
Virtual Internet Backbone for Multicast IP.
IP-Multicast is the class-D addressing scheme in IP implemented by Steve Deering
at Xerox PARC. It was adopted at the IETF March 1992 meeting and acquired the
name MBONE after the July 1992 IETF meeting.
IP Multicast-based routing allows distributed applications to achieve real-time
communication over IP wide area networks through a lightweight, highly threaded
model of communication.
Each network-provider participant in the MBONE provides one or more IP multicast
routers to connect with tunnels to other participants and to customers. The
multicast routers are typically separate from a network's production routers
since most production routers don't yet support IP multicast. Most sites use
workstations running the mrouted program, but the experimental MOSPF software
for Proteon routers is an alternative.
It is best if the workstations can be dedicated to the multicast routing
function to avoid interference from other activities and so there will be no
qualms about installing kernel patches or new code releases on short notice.
Since most MBONE nodes other than endpoints will have at least three tunnels,
and each tunnel carries a separate (unicast) copy of each packet, it is also
useful, though not required, to have multiple network interfaces on the
workstation so it can be installed parallel to the unicast router for those
sites with configurations like this:
+----------+
| Backbone |
| Node |
+----------+
|
------------------------------------------ External DMZ Ethernet
| |
+----------+ +----------+
| Router | | mrouted |
+----------+ +----------+
| |
------------------------------------------ Internal DMZ Ethernet
This configuration allows the mrouted machine to connect with tunnels to
other regional networks over the external DMZ and
the physical backbone network, and connect with
tunnels to the lower-level mrouted machines over the
internal DMZ, thereby splitting the load of the
replicated packets. The mrouted machine would not do
any unicast forwarding.
Note that end-user sites may participate with as little as one workstation that
runs the packet audio and video software and has a tunnel to a network-provider
node.
RFC 1112 gives the details.
FAQ.
(1994-11-11)
Nearby terms:
MB « MBASIC « Mbogo, Dr. Fred « MBONE » mbps
» MBS » MC
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