Re: [tcpm] TCP Protocol

"Scharf, Michael" <> Wed, 13 October 2021 17:00 UTC

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From: "Scharf, Michael" <>
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Thread-Topic: [tcpm] TCP Protocol
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Date: Wed, 13 Oct 2021 17:00:21 +0000
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Subject: Re: [tcpm] TCP Protocol
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For what it is worth, I believe that it is a valid question that is not entirely out-of-scope of TCPM.

As TSV-ART reviewer I quite frequently run into the term „layer-4 protocol“ for TCP, e.g., in documents from other IETF areas… 


And a 5-layer „hybrid“ reference model is used in a lot of books (e.g., Tanenbaum) and that sort of thinking is thus not uncommon – at least outside the IETF.


Michael - well, as professor ;-)



From: tcpm <> On Behalf Of
Sent: Wednesday, October 13, 2021 6:05 PM
To: Ron Smith <>
Subject: Re: [tcpm] TCP Protocol




It might be useful to review the charter of this WG (and thus the purpose of this list), as well as the Tao of the IETF; you can find both via search engines.


I’ll contact you further off-list with additional info.





Joe Touch, temporal epistemologist <> 

On Oct 12, 2021, at 10:44 AM, Ron Smith < <> > wrote:



My name is Ron Smith and I am a Cyber Warfare Instructor for the DoD and we
reference many of the RFCs on your site frequently throughout the course of
our instruction. One issue I'm having is that we reference a 4 layer TCP
model based on a couple of RFCs but I keep finding references to a 5-layer
model.  In fact, one of the tools we use, Wireshark, also utilizes
dissectors based on the 5-layer model.  Is there an updated RFC or some
guidance that pertains to this updated model?

Ron Smith

tcpm mailing list <>