Server Message Block Protocol

There are very many systems which can use the NetBIOS / NetBEUI interface or make use of the NetBIOS Frames Protocol, but perhaps one of the most important is the Server Message Block Protocol (SMB). The Server Message Block Protocol (SMB), is an application level protocol used by networking systems and operating systems such as Microsoft's Windows for Workgroups, Windows 95 / 98 / ME, LAN Manager, Windows NT, Windows 2000 and IBM's OS/2 and LAN Server, NetWare 6 and the SAMBA implementation and as such deserves special attention. The latest versions of the protocol are now known as the "Common Internet File System protocol".

An implementation of SMB is described in "Protocols for X/Open PC Interworking: SMB, Version 2", see Bibliography


According to the INTERNET-DRAFT document by christopher R Hertel draft-crhertel-smb-url-03.txt titled "SMB Filesharing URL Scheme"

" The Server Message Block protocol (SMB) was created in the 1980's by Dr. Barry Feigenbaum at IBM Corporation. It was later extended by IBM, 3Com, Intel, and Microsoft. "

In 1987 Microsoft announced the LAN Manager program and in 1988 IBM announced the OS/2 LAN Server, both use versions of the Server Message Block Protocol. Enhancements and changes to the protocol have been made and a history can be found at:" History of SMB

Some dates in the development of the protocol are given below:

Table 1. History of SMB and CIFS

Date Development
29 November 1989

SMB.TXT is the LM 2.0 protocol. Note: In the doc is calls LM 2.0 as LM 1.2 (it's original name before being renamed to LM 2.0).

Microsoft Networks SMB FILE SHARING PROTOCOL EXTENSIONS SMB File Sharing Protocol Extensions Version 3.0 Document Version 1.09

October 1992 Protocols for X/Open PC Interworking: SMB, Version 2
26 March 2001 The Storage Networking Industry Association (SNIA) produced a work-in-progress document: Common Internet File System (CIFS) Version: CIFS-Spec 0.9 Draft SNIA CIFS Work Group Work-in-Progress

Microsoft and a number of other companies, have proposed an updated version of SMB as an internet standard The Common Internet File System (CIFS).