About the Multicast Web Tuner

     Proxy Benefits:

    Move files closer to client to improve response speed when files are requested again.

    Share proxies so that clients can benefit from the request histories of other clients.

    Decoupling the clients from the server reduces server load and network traffic.

    Evolution of Proxy use:

a)    Direct communication between client and server

b)    All communication goes through proxy.  Proxy stores requested files and clients benefit on repeated requests.

c)    The system in b) works well when the high-latency connection is located between the server and the proxy.  A client with a high-latency connection to the proxy suffers.

d)    If each client has a companion proxy, the latency between the proxies is not detrimental.  Unfortunately, isoloated proxies do not share request histories.

Solution:  Servers multicast files to a set of companion proxies.  Server load is reduced, network traffic is reduced, proxies mutually share request histories, and clients experience low reponse delays.

    IB Multicast Web Tuner request cycle:

a)    First client requests a file from the proxy.  The proxy does not have a copy of the file and forwards the request to the server.

b)    Server multicasts the file to both proxies.  The first proxy relays the file to the requesting client.

c)    Second client requests the same file from it's proxy.

d)    Second proxy has the file due to the request from the first client and forwards it to the second client.

 
Page maintainer: Joe Touch
Last modified: Mon Jan 13 13:30:29 1997 
Copyright © 1996 by USC/ISI