RFC 2102 (rfc2102) - Page 2 of 23
Multicast Support for Nimrod : Requirements and Solution Approaches
Alternative Format: Original Text Document
RFC 2102 Nimrod Multicast Support February 1997 1 Introduction The nature of emerging applications such as videoconferencing, remote classroom, etc. makes the support for multicasting essential for any future routing architecture. Multicasting is performed by using a multicast delivery tree whose leaves are the multicast destinations. Nimrod does not propose a solution for the multicasting problem. There are two chief reasons for this. First, multicasting is a non- trivial problem whose requirements are still not well understood. Second, a number of groups (for instance the IDMR working group of the IETF) are studying the problem by itself and it is not our intention to duplicate those efforts. This attitude towards multicasting is consistent with Nimrod's general philosophy of flexibility, adaptability and incremental change. While a multicasting solution per se is not part of the "core" Nimrod architecture, Nimrod does require that the solution have certain characteristics. It is the purpose of this document to discuss some of these requirements and evaluate approaches towards meeting them. This document is organized as follows. In section 2 we discuss why multicasting is treated a little differently than unicast despite the fact that the former is essentially a generalization of the latter. Following that, in section 4 we discuss current approaches toward multicasting . In section 5, we give an example of how Nimrod multicasting may be done using PIM [DEF+94a]. For readers who do not have the time to go through the entire document, a summary is given at the end. This document uses many terms and concepts from the Nimrod Architecture document [CCS96] and some terms and concepts (in section 5) from the Nimrod Functionality document [RS96]. Much of the discussion assumes that you have read at least the Nimrod Architecture document [CCS96]. Ramanathan Informational
