Multicast Delivery Based on Unicast and
Seok‐Joo Koh, Shin‐Gak Kang, Dae Young Kim · 2001
Abstract— In spite of the numerous works recently made, IPmulticasting has not been widely deployed in the public Internet.WepresentarealisticalternativeschemeforIPmulticasting,whichis based on the unicast transport from a remote sender to a localsubnet and the multicastforwarding to receiverswithin the subnet.Index Terms— Feeder, IP multicast, subnet multicast. I. I NTRODUCTION F OR one-to-many multicast applications, it is agreed that IPmulticasting [1]–[3] is more efficient than the replicatedone-to-one unicast transports. Nevertheless, IP multicasting hasnot been widelydeployed in thepublicInternet. One ofthe mainreasons is that many ISPs still have much concern for implo-sion of multicast traffic into the networks. In particular, a largeamount of investment on the existing network is required for themulticast deployment including multicast-capable routers andsoftware. In fact, it does not seem that IP multicasting will bewidely deployed in the near future.We propose a realistic transport scheme as a short-term so-lution for Internet multicast applications, which can easily bedeployed without the legacy IP multicasting technologies [2].The proposed scheme is designed on the recognition that themulticast users are mainly distributed in the private enterprisesubnetworks, which is typically based on IEEE 802 LAN [4],[5], and that the multicast forwarding can be easily achievedwithin a subnetwork, compared to the WANs.II. D