Patent attributes
A method of signaling between Ethernet transceivers along a link is disclosed. The method includes advertising first and second supported data rates between the transceivers during an autonegotiation sequence. The link is then trained to train transceiver operating parameters with a training sequence of symbols. The training includes initiating the training sequence to support the first data rate, determining whether the link can operate at the first data rate, and transferring control information requesting a retrain at a second data rate different than the first data rate if the link cannot support the first data rate. The link is retrained, in response to the control information, to train the parameters for operation at the second data rate. The retraining is carried out without repeating the autonegotiation sequence. The link is then operated in a data transfer mode at the second data rate.