Server Message Block

protocol (SMB) A client/server protocol that provides

file and printer sharing between computers. In addition SMB

can share serial ports and communications abstractions such

as named pipes and mail slots. SMB is similar to remoteprocedure call (RPC) specialised for file system access.

SMB was developed by Intel, Microsoft, and IBM in the

early 1980s. It has also had input from Xerox and 3Com.

It is the native method of file and print sharing for

Microsoft operating systems; where it is called MicrosoftNetworking. Windows for Workgroups, Windows 95, and

Windows NT all include SMB clients and servers. SMB is also

used by OS/2, Lan Manager and Banyan Vines. There are

SMB servers and clients for Unix, for example Samba and

smbclient.

SMB is a presentation layer protocol structured as a large

set of commands (Server Message Blocks). There are commands

to support file sharing, printer sharing, userauthentication, resource browsing, and other miscellaneous

functions. As clients and servers may implement different

versions ("dialects") of the protocol they negotiate before

starting a session.

The redirector packages SMB requests into a network controlblock (NBC) structure that can be sent across the network to

a remote device.

SMB originally ran on top of the lower level protocols

NetBEUI and NetBIOS, but now typically runs over TCP/IP.

Microsoft have developed an extended version of SMB for the

Internet, the Common Internet File System (CIFS), which in

most cases replaces SMB. CIFS runs only runs over TCP/IP.

Just what is SMB?.

IBM protocols.

Microsoft SMB/CIFS documents.

(1999-08-08)