The SMB protocol was developed by IBM in 1983 and was made public in the OS/2 network operating systems LAN Manager and LAN Server. The Windows operating system series has been backward compatible with SMB and allows communication between versions of the same operating system. For example, Samba enables Linux users to use the Server Message Block. It also provides cross-platform communication. However, the current SMB specification does not require a Windows operating environment.
SMBs can use a separate transport protocol for file transfers. The NetBIOS over NetBEUI protocol is used to support NetBIOS. It is supported on Windows NT and 2000, but is not supported in Windows XP. SMB can be used with no separate transport protocol and can be used with existing network infrastructure. It can be used with IPX/SPX. Alternatively, it can be used without separate protocols.
SMB supports two levels of security checks: user-level authentication and share-level authentication. A share is a shared directory, file, or printer service. A user is a client, requesting to access a file or directory on the network. If this security check is successful, the client is allowed to access the server. In some instances, SMB is a secure network protocol, which is used by many businesses. Further, SMB is widely used as a standard networking protocol.