RFC 793, "Transmission Control Protocol", September 1981

Note: This RFC has been obsoleted by RFC 9293

Errata ID: 6281
Status: Held for Document Update
Type: Editorial
Publication Format(s) : TEXT
Reported By: Merlin Büge
Date Reported: 2020-09-06
Held for Document Update by: Martin Duke
Date Held: 2020-10-12

Section 3.4 says:

  At line 4, TCP A responds with an empty segment containing an ACK for
  TCP B's SYN; and in line 5, TCP A sends some data.  Note that the
  sequence number of the segment in line 5 is the same as in line 4
  because the ACK does not occupy sequence number space (if it did, we
  would wind up ACKing ACK's!).

It should say:

  At line 4, TCP A responds with an empty segment containing an ACK for
  TCP B's SYN; and in line 5, TCP A sends some data.  Note that the
  sequence number of the segment in line 5 is the same as in line 4
  because the ACK does not occupy sequence number space (if it did, we
  would wind up ACKing ACKs!).

Notes:

last line: "ACK's" -> "ACKs"

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