Mbone stands for multicast backbone and was an experimental approach to use tunnels to enable multicast as an upper layer of the Internet. 

Internet WebCredit: http://www.semblem.com/internet-rule-1-you-dont-matter/The Internet is a web of connections, linking servers to computers to allow users access to websites and the information stored on outside servers (like the pictures in your Flicker account).  When you want to access a website, such as Wikipedia, your computer sends a message to servers nearby requesting access to the mid level domain Wikipedia with the top domain .org, and then directs you to the server where the website is hosted.

Internet Protocol (IP) multicast traffic is when data is sent to multiple people simultaneous, and thus is primarily used for streaming media and communication software where more than one person receives information at the same time.  Historically, the servers the Internet run on handle information on a one on one basis, answering requests as they come in.  Multicasting however, allow the sending of data from one location to several, like a live webcast of an event, or from many locations to all those connected to it, like video conferences with more than two members.  The data packet is only sent once, as opposed to multiple times towards each user desiring it.  It is also two way, and usually operates in real time.

Mbone then, connected multicast capable networks over the Internet.  And as it was based off the Internet, which is already paid for to ISPs, the service was offered free of charge to those with the right equipment.


Van Jacobson, Steve Deering and Stephen Casner invented the Mbone network in 1992, a few years before the Internet was adopted by the general public.  However, it wasn’t used until November 1994, when a Rolling Stones concert in Dallas was multicast.  Come 1995, Mbone links showed up in Russia and Antarctica.

However, shortly after that the experimant became inoperable. IP multicast however, still works and is in use today.  Manily by universities, as it is rather complex to set up for average users, but recently there has been renewed interest in the tunnelling procedure Mbone used to make multicasting more accessiable.  As such, select routers do enable multicasting.


While MBone existed to enable multicast traffic, it’s specific purpose was to minimize the data required for audio/video conferencing among a group of users. It was also used for shared collaborative workspaces.

How it Works

As many routers did not, and still do not, support IP multicast; it’s hard to commercialize because it’s not easy to access control capabilities of the network and Internet service providers (ISPs) have difficulty charging for the service and don’t want to broadcast it. Thus Mbone worked by having multicast data packets placed in unicast packets and sent through tunnels. Tunnel protocols on both the sending and receiving end were set up to handle the data traffic and served as point-to-point links.  By having multicast date packets encapsulated in unicast ones, non-multicast routers didn’t disrupt the path of the information.