I don't really have anything to add to the discussion, but I thought I should point out that TCP/IP is not based on the OSI 7-layer model. There was a good diagram of the correspondence between the layers of TCP/IP and the layers of OSI in my college Networking textbook, but this is the best I can find online:
http://www.hummingbird.com/support/nc/nfs/dos/general2.html > -----Original Message----- > From: Chris McCulloh [mailto:[EMAIL PROTECTED]] > Sent: Tuesday, November 27, 2001 10:32 PM > To: Tarek Koudsi > Cc: [EMAIL PROTECTED] > Subject: Re: please help with SSL > > > Tarek Koudsi wrote: > > > I would highly appreciat eit if someone could answer > > this quesiton? is it possible in SSL for the receiver to > > reorder SSL record blocks > > that arrive out of order? if yes how? if not, why not? > > > Please somebody correct me if I'm wrong here, but based on the OSI > model, SSL (and it's newer replacement, TLS) runs at the > Transport layer > (hence, the TL in TLS), while TCP is a gateway between the Transport > Layer and the Network Layer. Because TCP itself handles > retransmissions > and packets arriving in/out of order, I don't believe it's > possible for > SSL blocks to come in out of order when using TCP. > > With UDP, however, the reliability of a "connected" protocol > is out the > window -- and I suppose it'd be possible, in theory, if you > were using > UDP and SSL. But keep in mind -- this is not possible to do, > according > to the SSLv3 spec > http://www.netscape.com/eng/ssl3/draft302.txt "At the > lowest level, layered on top of some reliable transport > protocol (e.g., > TCP[TCP]), is the SSL Record Protocol...At the present time SSL is > implemented using TCP/IP as the base networking technology." > > chris >
