Talk:Maximum segment size

message: It would be nice if the article could point out why an MSS value is necessary, since we already have an MTU and a PMTU; isn't the MSS redundant? 195.56.53.118 22:32, 2 November 2006 (UTC)
replies: text: I'd like to know this too. I came here specifically to find out an answer to this because I cannot see the point of it when there's an MTU 112.204.173.97 (talk) 02:07, 8 May 2022 (UTC)
thread_title:  Why MSS is needed at all? 

message: I'm pretty sure that MTU is a parameter used by the IP stack software or something else at about that level.  It says, in effect "If you encounter an outbound packet larger than this, fragment it."  MSS is a parameter used by the program actually generating messages that says "block your message into chunks no larger than this so we don't have to fragment it later".  I think MSS might apply only to TCP whereas MTU applies to UDP and any other data scheme that uses IP.  PMTU is an algorithm/technique that is used to dynamically determine the maxmum usable MTU for a link.
It does seem to me also that one article with a couple of links could probably handle all three concepts.  
Yes, I believe that the TCP header is almost always 40 bytes.  It's the 'almost' that troubles me.  See  and search for the phrase "TCP options expanding the header".  TCP options?
I considering getting back into working on Wikipedia after a lapse of several years.  But it's a vastly different (and better) resource than it was back when there were only a few thousand articles and the objective was to get credible content.  I don't plan to start up by tinkering with articles on subjects that I possibly don't understand all that well.  I'll check back in a month or so and see where this stands 72.92.156.173 14:00, 23 November 2006 (UTC)
thread_title:  Comments on the above 

message: The article should point out that MSS is a TCP term; it starts by defining it
as some general thing between "communication devices", then slips over to
talk about TCP as if it was a special case.
(Or has the term been generalized, and I've missed it?)
JöG (talk) 11:52, 24 March 2009 (UTC)
thread_title:  MSS is TCP-specific 

message: If you put MSS and MTU into the correct layers it becomes much clearer. MTU is the maximum physical amount of data that can be moved in one piece on layer 2, usually limited by hardware.
Since layer 3 (IP) employs layer 2 and is in turn used by layer 4 (TCP), both of these must not transmit more data than can be physically transported. For TCP's layer 4 this amount is MSS = MTU - overhead (2x20 bytes for IPv4 over Ethernet).
Sometimes however hardware restrictions do not directly apply, so MSS is a matter of arbitration (e.g. PPP). -- Zac67 (talk) 20:08, 18 August 2009 (UTC)
thread_title:  MSS vs MTU 

message: "The likelihood of such fragmentation can be minimized by keeping the MSS as small as reasonably possible."
Why? Shouldn't it be larger, so that the computer can receive more - and then be able to handle even larger segments without the needs to fragment them?  —Preceding unsigned comment added by 84.110.125.93 (talk) 05:22, 1 November 2010 (UTC)
thread_title:  Conclusion needs clarification 

message: Prior content in this article duplicated one or more previously published sources. The material was copied from: http://searchnetworking.techtarget.com/definition/maximum-segment-size. Infringing material has been rewritten or removed and must not be restored, unless it is duly released under a compatible license. (For more information, please see "using copyrighted works from others" if you are not the copyright holder of this material, or "donating copyrighted materials" if you are.) For legal reasons, we cannot accept copyrighted text or images borrowed from other web sites or published material; such additions will be deleted. Contributors may use copyrighted publications as a source of information, but not as a source of sentences or phrases. Accordingly, the material may be rewritten, but only if it does not infringe on the copyright of the original or plagiarize from that source. Please see our guideline on non-free text for how to properly implement limited quotations of copyrighted text. Wikipedia takes copyright violations very seriously, and persistent violators will be blocked from editing. While we appreciate contributions, we must require all contributors to understand and comply with these policies. Thank you.  NortyNort  (Holla) 06:25, 4 June 2011 (UTC)
thread_title:  Copyright problem removed 

message: This edit caught my eye. It has been some years since I was up to speed on this stuff and really don't have time to clarify this right now. The following RFCs might be useful if anyone else wants to do this: 879, 6691, 7805; that list is probably not complete. Wtmitchell  (talk) (earlier Boracay Bill) 18:38, 20 June 2019 (UTC)
replies: text: Likewise I am not up to date but I reverted the IP's claim as unsourced. It sounds very unlikely. Johnuniq (talk) 23:34, 20 June 2019 (UTC)
thread_title:  536, etc.