11. Application-Layer Multicast

Abstract

Since the early days of the Internet, extending routing capabilities beyond point-to-point communication has been a desired feature, mostly as a means of resource discovery. The limited size of the Internet at that time permitted the technique of broadcasting a single packet to every possible node. With its growth, Internet-wide broadcasting became increasingly expensive which imposed constraining the scope of broadcast packets to end points that expressed interest in receiving packets of a specific service (Selective Broadcast [612]). This was in fact the first attempt to offer indirectly a group communication service over the Internet.