Wireshark mailing list archives
Re: TCP windows update
From: Guy Harris <guy () alum mit edu>
Date: Tue, 1 Mar 2011 13:23:19 -0800
On Mar 1, 2011, at 12:45 PM, Andrej van der Zee wrote:
Maybe a silly question, but can a Windows update be piggy backed with a data segment, or is it always contained in a zero-length data segment?
As Stephen said, "Each TCP segment has a window size"; nothing in RFC 793 says you can't put data in a TCP segment that has an "advertised window" value different from the one in the previous segment.
Also, can a Windows update contain an ACK number for non-ACKed data segments?
Again, nothing in RFC 793 disallows that. In fact, once a connection is established, *every* segment contains an ACK number - to quote RFC 793: Acknowledgment Number: 32 bits If the ACK control bit is set this field contains the value of the next sequence number the sender of the segment is expecting to receive. Once a connection is established this is always sent. It might be the same ACK number as the previous segment in the same direction, but it's always there. ___________________________________________________________________________ Sent via: Wireshark-users mailing list <wireshark-users () wireshark org> Archives: http://www.wireshark.org/lists/wireshark-users Unsubscribe: https://wireshark.org/mailman/options/wireshark-users mailto:wireshark-users-request () wireshark org?subject=unsubscribe
Current thread:
- Re: TCP windows update Andrej van der Zee (Mar 01)
- Re: TCP windows update Guy Harris (Mar 01)
- Re: TCP windows update Andrej van der Zee (Mar 01)
- Re: TCP windows update Guy Harris (Mar 01)
- Re: TCP windows update Andrej van der Zee (Mar 01)
- Re: TCP windows update Martin Visser (Mar 01)
- Re: TCP windows update Andrej van der Zee (Mar 01)
- Re: TCP windows update Guy Harris (Mar 01)