The newly released IE5 has a proxy autodiscovery feature which has significant practical implications for global bandwidth use. Its hard to know how many web clients are proxied today. Its probably much less than 50% (including AOL users). The main reason appears to be that most clients are not configured for it by default. With IE5, if ISPs create a CNAME called wpad and provide a file called wpad.dat on port 80 that uses the Netscape proxy guidelines: http://home.netscape.com/eng/mozilla/2.0/relnotes/demo/proxy-live.html Then IE5 will automatically use those proxies for HTTP. This is as transparent to the end user as dynamic IP assignment or HTTP redirection. 12 months from now when the majority of PCs are shipping with this as the default browser, it would seem that proxies will be significantly more relevant to traffic shaping than they are today. jg@meer.net