资料来源 : Free On-Line Dictionary of Computing

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
        network}s through a lightweight, highly {thread}ed 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 (http://www.eit.com/techinfo/mbone/mbone.html)}.
     
        (1994-11-11)