I kinda working on my own tcp/ip lib and this is how I interprete it.
Your dumb terminal scripter makes connection
that activates PPP (with LCP confsync)
if that get an IP and return good then you can splat (encapulate)
IP/TCP/UDP packets
out the line
er. and I must warn you I havnt got a working version so dont listen to me,
I am a techno moron.
Why do they call it TCP/IP ? that sound reversed. it should be
IP/TCP-UDP as that makes sense in
my head.
At 02:25 AM 3/1/02 -0500, Bill Cunningham wrote:
I have received several responses and most people say it's in the data
layer, and a couple of people think it's in the network layer. I don't
really pay much attention to the OSI model, I think it complicates the
complicated. I try to focus more on TCP/IP. Does PPP establish a link, then
terminate, or continue throughout session in UDP and TCP? I posted this
question on the PPP mailing list with less familiaritive response than ietf
general list.
----- Original Message -----
From: "Brian Lloyd" <brian(_at_)lloyd(_dot_)com>
To: "Bill Cunningham" <billcu(_at_)CITYNET(_dot_)NET>
Cc: <ietf(_at_)ietf(_dot_)org>
Sent: Thursday, February 28, 2002 11:52 AM
Subject: Re: PPP
At 03:55 AM 2/28/2002, you wrote:
In what layer is PPP in the TCP/IP suite?
I have read some of the other responses and it reinforces my belief that
most people don't understand PPP's relationship to IP and either the
5-layer (internet) or 7-layer (ISO) models.
PPP is really both the link and lower network layers. (The ISORMites
discovered that layer three was really several layers in itself but found
it difficult to say that the 7-layer model was really a 9-layer model so
they created sublayers, i.e. layers 3A, 3B, and 3C. Something about
Padlipsky comes to mind here.) The best way to think of PPP is a
degenerate
network of two nodes, not a link between two devices. If you think of it
in this way, things like multilink and L2TP begin to make some sense. The
problem occurs when people forget this.
The way that I think of it is that the LCP negotiation represents
configuration of the link layer while the NCP negotiation configuration at
the network layer.
And I continue to kick myself for allowing negotiation of multilink as
part
of LCP instead of doing it after authentication. I fear that this helped
screw up L2TP too. I admit I caved to people who were worried about how
long it took PPP to complete negotiation, something that just isn't very
important.
Brian Lloyd
brian(_at_)lloyd(_dot_)com
+1.530.676.1113 - voice
+1.360.838.9669 - fax