One embodiment provides a method for enabling class-based credit flow control for a network node in communication with a link partner using an Ethernet communications protocol. The method includes receiving a control frame from the link partner. The control frame includes at least one field for specifying credit for at least one traffic class and the credit is based on available space in a receive buffer associated with the at least one traffic class. The method further includes sending data packets to the link partner based on the credit, the data packets associated with the at least one traffic class.