Hi Douglas, They are parallel implementations of the same functionality. Essentially separate source, but same design. Hope that helps.
Regards, Kristian Smith Escalation Engineer | Microsoft(r) Corporation Email: [email protected] -----Original Message----- From: Douglas Bagnall <[email protected]> Sent: Tuesday, January 13, 2026 4:52 PM To: Kristian Smith <[email protected]> Cc: Microsoft Support <[email protected]>; [email protected] Subject: Re: [EXTERNAL] is MS-DRSR 4.1.10.5.21 CompressOrDecompressWin2k3 the same as MS-WUSP 2.1.1.1 CompressOrDecompressWin2k3 ? - TrackingID#2512240040003184 hi Kristian, I am still interested to know whether they are exactly the same or not. thanks Douglas On 14/01/2026 13:38, Kristian Smith wrote: > Hi Douglas, > > I reached out to the engineering team and we determined that the > discrepancies are in MS-DRSR. MS-DRSR should reflect " a match length of up > to 65,535 bytes + 3 bytes" as well as " This scheme is good for lengths of up > to 279". I've submitted a bug against the document and you should see this > updated in a future document release. > > Thank you for helping us keep the docs up to date. Please let me know if you > have any further questions. > > Regards, > Kristian Smith > Escalation Engineer | Microsoft(r) Corporation > Email: [email protected] > > -----Original Message----- > From: Tom Jebo <[email protected]> > Sent: Wednesday, December 24, 2025 8:57 AM > To: Douglas Bagnall <[email protected]>; > [email protected] > Cc: Interoperability Documentation Help <[email protected]>; Microsoft > Support <[email protected]> > Subject: RE: [EXTERNAL] is MS-DRSR 4.1.10.5.21 CompressOrDecompressWin2k3 the > same as MS-WUSP 2.1.1.1 CompressOrDecompressWin2k3 ? - > TrackingID#2512240040003184 > > [dochelp to cc] > [support mail to cc] > > Hi Douglas, > > Thanks for your request regarding MS-DRSR 4.1.10.5.21 and MS-WUSP 2.1.1.1. > One of the Open Specifications team members will respond to assist you. In > the meantime, we've created case 2512240040003184 to track this request. > Please leave the case number in the subject when communicating with our team > about this request. > > Best regards, > Tom Jebo > Microsoft Open Specifications Support > > -----Original Message----- > From: Douglas Bagnall <[email protected]> > Sent: Tuesday, December 23, 2025 3:40 PM > To: Interoperability Documentation Help <[email protected]>; > [email protected] > Subject: [EXTERNAL] is MS-DRSR 4.1.10.5.21 CompressOrDecompressWin2k3 the > same as MS-WUSP 2.1.1.1 CompressOrDecompressWin2k3 ? > > hi Dochelp. > > The MS-DRSR and MS-WUSP definitions of CompressOrDecompressWin2k3 look very > similar. > Are they really the same procedure? > > If they are in fact the same, my next question is which document is most > correct. > I haven't looked closely, but I see these differences: > > MS-WUSP: This scheme is good for lengths of up to 279 > MS-DRSR: This scheme is good for lengths of up to 278 > > MS-WUSP: a match length of up to 65,535 bytes + 3 bytes > MS-DRSR: a match length of up to 32,768 bytes + 3 bytes > > Perhaps one has been updated and not the other? > > > In November 2022[1] I asked if MS-XCA 2.3 and 2.4 "Plain LZ77" was the same > as the MS-DRSR procedure. The answer was "MS-DRSR uses a different API than > what MS-XCA uses", which I took to mean that even if it was initially > intended that they were the same, they could easily be accidentally > different. I guess my first question could be answered in the same way -- are > these using the same shared library function? > > [1] https://lists.samba.org/archive/cifs-protocol/2022-November/003902.html > > cheers, > Douglas > _______________________________________________ cifs-protocol mailing list [email protected] https://lists.samba.org/mailman/listinfo/cifs-protocol
