Your mileage may vary. Advertiser's disclaimer Email  From: Steven French, Senior Software Engineer, IBM To: Chris Hertel Chris, Hope things are going well in the cold north... I thought the following info would be interesting to you. I met the original "inventor" of SMB a few years ago - Dr. Barry Feigenbaum - who back in the early 80's was working on network software architecture for the infant IBM PCs, working for IBM in the Boca Raton plant in Florida. He mentioned that it was first called the "BAF" protocol (after his initials) but he later changed it to SMB. In the early DOS years IBM and Microsoft (with some input from Intel and 3Com) contributed to it but by the time of the first OS/2 server version (LANMAN1.0 dialect and later) Microsoft did much of the work (for "LAN Manager" and its relatives). | Like NetBIOS, the Server Message Block protocol originated a long time ago at IBM. Microsoft embraced it, extended it, and in 1996 gave it a marketing upgrade by renaming it "CIFS." Over the years there have been several attempts to document and standardize the SMB/CIFS protocol: -
Microsoft keeps an archive of documentation covering older versions of SMB/CIFS. The collection spans a period of roughly ten years, starting at about 1988 with the SMB Core Protocol. The collection is housed, it seems, on a dusty FTP server in a forgotten corner of a machine room somewhere in the Pacific Northwest. The URL for the CIFS archive is ftp://ftp.microsoft.com/developr/drg/CIFS/. -
In 1992, X/Open (now known as The Open Group ) published an SMB specification titled Protocols for X/Open PC Interworking: SMB, Version 2 . The book is now many years out of date and SMB has evolved a bit since its publication, yet it is still considered one of the best references available. [1] The Open Group is a standards body so the outdated version of SMB described in the X/Open book is, after all, a standard protocol. [1] The X/Open SMB documentation is out of print, but electronic copies are now available online (free registration required). See http://www.opengroup.org/products/ publications /catalog/, and look for documents #C195 and #C209. -
A few years later, Microsoft submitted a set of CIFS Internet Drafts to the IETF ( I nternet E ngineering T ask F orce), but those drafts were somewhat incomplete and inaccurate; they were allowed to expire. Microsoft's more recent attempts at documenting CIFS (starting in March, 2002) have been rendered useless by awkward licensing restrictions, and from all accounts contain no new information. [2] The expired IETF Internet Drafts (by Paul Leach and Dilip Naik) are still available from the Microsoft FTP server described above and other sources around the web. [2] I must rely on anecdotal evidence to support this claim. Due to the licensing restrictions, I have not read these documents, which were released in March of 2002. -
The CIFS Working Group of the S torage N etwork I ndustry A ssociation (SNIA) has published a CIFS Technical Reference based on the earlier IETF drafts. The SNIA document is neither a specification nor a standard, but it is freely available from the SNIA website. Without a current and authoritative protocol specification, there is no external reference against which to measure the "correctness" of an implementation, and no way to hold anyone accountable. Since Microsoft is the market leader, with a proven monopoly on the desktop, the behavior of their clients and servers is the standard against which all other implementations are measured. Jeremy Allison, the Samba Team's First Officer, [3] has stated that "The level of detail required to interoperate successfully is simply not documentable." One reason that this is true is that Microsoft can "enhance" SMB behavior at will. Combined with the dearth of authoritative references, this means that the only criteria for a well-behaved SMB implementation is that it works with Microsoft products. As a result, subtle inconsistencies and variations have crept into the protocol. They are discovered in much the same way that a dog-owner discovers poop in the yard in springtime when the snow melts. [4] [3] ...and Tactical Officer. He's the one with the prosthetic forehead. [4] I live in Minnesota, where it most definitely snows in winter. I share my home with a Pembrokeshire Welsh Corgi and a Golden Retriever, so the springtime scenario described above is vividly real and meaningful to me. Some of my Australian Samba Team friends have suggested that people in other parts of the world may find it less familiar. Use your imagination . Many people dread spring chores, but spring also brings the flowers. The children play, the dog chases a butterfly , the birds sing... and it all seems suddenly worthwhile. It's the same with the work we have ahead. Things are not really too bad, once you've gotten started.  |
