Bill, This slide is confusing, for sure. The reason I posted the link was the comparison between the OSI and the TCP/IP models. Michel. > From: Bill Cunningham [mailto:billcu@citynet.net] > http://dast.nlanr.net/Training/DCWJuly99/kai_tcpip/sld008.htm > I looked at this page of one of the links you sent me. Notice > at the Internet and Transport levels it simply says, Application > data (datagram ?), TCP header, could this be a datagram, or > maybe a packet. Then at the Internet level, application data, > TCP header and IP header. Now according to rfc 1122, we know that - > o application data, tcp header > o application data, tcp header, and ip header. > Are both datagrams. Wow IMHO what a mix up. Unless you know the > name of the protocol and where you know (or think) it is in > TCP/IP, you're lost.