Ethernet flow control is a mechanism for temporarily stopping the transmission of data on Ethernet family computer networks. The first flow control mechanism, the PAUSE frame, was defined by the IEEE 802.3x standard.

The follow-on priority-based flow control, as defined in the IEEE 802.1Qbb standard, provides a link-level flow control mechanism that can be controlled independently for each Class of Service (CoS), as defined by IEEE P802.1p. The goal of this mechanism is to ensure zero loss under congestion in data center bridging (DCB) networks.