SFU stands for Selective Forwarding Unit. Also known in the specifications as SFM (Selective Forwarding Middlebox).

At times, the term is used to describe a type of video routing device, while at other times it will be used to indicate the support of routing technology and not a specific device.

An SFU is capable of receiving multiple media streams and then decide which of these media streams should be sent to which participants.

Common technologies used with an SFU include simulcast, temporal scalability and SVC.