Core Based Trees (CBT) An Architecture for Scalable Inter-Domain Multicast Routing

Document Type Expired Internet-Draft (idmr WG)
Authors Paul Francis  , Jon Crowcroft  , Anthony Ballardie 
Last updated 1993-03-01
Stream Internet Engineering Task Force (IETF)
Intended RFC status (None)
Expired & archived
Stream WG state WG Document
Document shepherd No shepherd assigned
IESG IESG state Expired
Consensus Boilerplate Unknown
Telechat date
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft can be found at


One of the central problems in one-to-many wide-area communications is forming the delivery tree - the collection of nodes and links that a multicast packet traverses. Significant problems remain to be solved in the area of multicast tree formation, the problem of scaling being paramount among these. This draft presents a new scalable multicast architecture, followed by a protocol description, that can provide low-cost, relatively simple, and efficient multicast routing. We also show how this architecture is decoupled from (though dependent on) unicast routing, and is therefore easy to install in an internet that comprises multiple heterogeneous unicast routing algorithms. A mailing list is in place in (subscribe to to discuss this and other inter-domain multicast routing issues.


Paul Francis (
Jon Crowcroft (
Anthony Ballardie (

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)