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Learning to manage Internet traffic

Test of possible solutions

Started using wwwcache.infn.it:3128 accessed from a local proxy (a Cern httpd with 100 M storage) www.ba.infn.it:8001. The proxy.conf file is set in such a way that requests to infn.it make no use of the proxy.

The proxy solution

The idea behind the proxy is the following:let's suppose that you are node A and you are connected very badly to node C, but node B is very well connected with both you and C; then you can speed the access to C, simply by using B as a proxy. This means in practical terms that you install a server on B and on Netscape define B as your proxy. Netscape will send all your requests through B.
For example www.ba.infn.it (our site) is very well connected to Cern but not with North America. Since Cern is very well connected with Nort America, by using a proxy in Cern you can improve a lot your speed of connection with North America. How much?
A=www.ba.infn.it
B=www.cern.ch
C=www.altavista.digital.com
ping A->C 380 ms 50% packet loss
ping A->B 91 ms 0% packet loss
ping B->C 210 ms 5% packet loss
We have at least a tripling of the speed from A->C by using B as proxy.

What are the best proxies

Since www.ba.infn.it is on the Italian backbone connected to the European academic backbone, any site on this backbone well connected with B is a good proxy. If B is North America then we must exclude now(17 Oct 96) all italian academic sites all badly connected with America.

The INFN cache project

This INFN project is trying to address the problem of traffic jams on the Italian backbone by creating a hierarchy of cache servers. More on this page. I have also collected here messages among the group members. In Bari we should use wwwcache.lnf.infn.it:8080 or wwwcache.infn.it:3128
The use of the second should ensure a better service since it requires less hops in the connection to America. For example develop.iglobal.net (a site in Usa with a traceroute gateway) is 22=16+6 hops from Bari using the lnf proxy but only 16=13+3 using the cnaf proxy.(The number of hops for a direct connection from Bari is 16).

A quick check done by reloading the altavista.digital.com home page for a minute shows the following: with the following speeds bari-cnaf=42ms(0% packet loss) bari-altavista=273(27%) I can reload the page 17 times with a direct connection and only 6 times by using the proxy. Also when I use the proxy the connection seems sometime to get stuck and I have to stop and try again. So, it seems that with these speeds using the proxy will only make worse a slow connection with NorthAmerica.

Installing squid

Squid is the software to be installed. This software should run with no problems on our Digital OSF/1 machines.

Last updated: 1 may 1997