SMB – (1) Server Message Block – a Microsoft Windows file system access protocol. SMB protocol requires many back-and-forth admin handshakes that increase overall network session time.

Microsoft SMB session diagram.

Microsoft has reduced the chattiness of SMB over time, from its introduction with SMB 1.0 in 1990. SMB 2.0 in 2006 saw the command and sub-command total being lowered from over 100 to 19. SMB 3.0 in 2012 reduced chattiness and accelerated transfer speed even more by adding the SMB Direct Protocol, which used remote direct memory access, and SMB Multichannel, meaning a session could use multiple TCP/IP connections.

SMB – (2) Small and Medium Business.