The Virtual Multicasting Approach to Bandwidth Conservation
Brynn Andrew and  Philip Machanick
Department of Computer Science
University of the Witwatersrand

Virtual Multicast (VMC) exploits short-term similarities in Internet
traffic to save bandwidth and reduce congestion. Its implementation
requires modification of aspects the HTTP specification, which is
motivated by the expected benefits of the method: reclamation of
bandwidth lost due to redundant network data and latency savings as
seen by users.