Not to interrupt a discussion by adding measured data, but there is some collected data on MTU sizes around the net. I believe kc has some packet statistics data online at NLANR. Alternately, there is some @Home packet size data (from Mike Schwartz) online in PDF format at: ftp://ftp.home.net/pub/rja/home-pkt-dist.pdf Folks perusing the @Home data should keep in mind that nearly all residential customers have 10baseT Ethernet access to the Internet. So we have near zero packets larger than Ethernet MTU. :-) Ran