A Selective Forwarding Unit (SFU) is a service for optimizing the amount of streams sent in a room by forwarding media to a central server. This server can then smartly route and multiplex those media streams between users in a call. This decreases bandwidth required for multi-party calls and the amount of load on client software. The SFU/MCU is also required to be turned on for recording sessions. 

Learn more about Temasys SFU/MCU