Multicast routing in datagram internetworks and extended LANs

Stephen E. Deering, David R. Cheriton
1990 ACM Transactions on Computer Systems  
Multicasting, the transmission of a packet to a group of hosts, is an important service for improving the efficiency and robustness of distributed systems and applications. Although multicast capability is available and widely used in local area networks, when those LANs are interconnected by storeand-forward routers, the multicast service is usually not offered across the resulting internetwork. To address this limitation, we specify extensions to two common internetwork routing
more » ... nce-vector routing and link-state routing-to support low-delay datagram multicasting beyond a single LAN. We also describe modifications to the single-spanning-tree routing algorithm commonly used by link-layer bridges, to reduce the costs of multicasting in large extended LANs. Finally, we discuss how the use of multicast scope control and hierarchical multicast routing allows the multicast service to scale up to large internetworks. 1 Some applications have (unfortunately) implemented multicasting by using the network's broadcast addressing facility, relying on software filtering in the receiving hosts. This approach incurs undesirable overhead on those hosts that must receive and discard unwanted packets, overhead that gets worse as more and more applications use multicasting. Fortunately, this problem can be avoided in modern LANs, such as Ethernet and other networks conforming to the IEEE 802 [16] standards, which provide multicast addresses that can be recognized and filtered by host interface hardware.
doi:10.1145/78952.78953 fatcat:lhl2uypc2fakties5zcdmce7se