Server Message Block

Server Message Block (SMB) is a client/server protocol that provides file and printer sharing between computers. In addition SMB can share serial ports and communications abstractions such as s and s. SMB is similar to (RPC) specialised for file system access.

History
SMB was developed by Intel, Microsoft, and IBM in the early 1980s, with input from Xerox and. It is the native method of file and print sharing for operating systems from Microsoft, where it was referred to as Microsoft Networking. , Windows 95, and Windows NT all included SMB clients and servers. SMB is also used by, , and. There are SMB servers and clients for Unix, such as and.

Microsoft developed an extended version of SMB for the Internet, the (CIFS), which in most cases replaces SMB, though CIFS runs only runs over TCP/IP.

Description
SMB is a protocol structured as a large set of commands (Server Message Blocks). There are commands to support file sharing, printer sharing, user, 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 control block (NBC) structure that can be sent across the network to a remote device. SMB originally ran on top of the lower level protocols and, but now typically runs over TCP/IP.