Vint, > vinton g. cerf wrote: > Michel, > your drawing of TCP/IP is NOT the model I used in > the design of TCP/IP. [Thanks for the historical precisions] My understanding is that the TCP/IP model is de-facto, opposed to de jure for the OSI model. Below are the top ten matches searching for "tcp/ip model" on google; basically none is the same; some have four layers, some have five, the names are not consistent. Some years ago I tried to teach the TCP/IP model and I had to spend hours explaining why "my" vision of the TCP/IP model was not the same as they have seen somewhere else (you know, if they've seen it on the Internet, same as they've seen it on CNN, it must be true). I'm having trouble explaining to students why a reference model has variable definitions. If this: +---+-------------+ ! 5 ! Application ! +---+-------------+ ! 4 ! Transport ! +---+-------------+ ! 3 ! Internet ! +---+-------------+ ! 2 ! Link ! +---+-------------+ ! 1 ! Physical ! +---+-------------+ Is what you define as being the TCP/IP model (I don't think anybody would challenge *you* on this), would you please write an RFC about it so we can avoid what is below? http://www.pku.edu.cn/academic/research/computer-center/tc/html/TC0102.h tml http://www.indianest.com/computing/networking/n003.htm http://www2.themanualpage.org/networks/networks_tcpip.php3 http://www.8052.com/tcpip/ http://www.microsoft.com/windows2000/en/server/help/default.asp?url=/win dows2000/en/server/help/sag_TCPIP_ovr_model.htm http://dast.nlanr.net/Training/DCWJuly99/kai_tcpip/sld005.htm http://www.unm.edu/~network/presentations/course/chap2/sld018.htm http://academic.regis.edu/jguhlke/osi.ppt http://www.interex.org/pubcontent/enterprise/jul99/f1eltoft.html http://www.linuxsa.org.au/meetings/1998-02/conflinux/tcpipmodel.html Regards, Michel.