On Friday 04 June 2021 20:27:33 Russell King (Oracle) wrote: > 802.3 defined 1000base-X which is a fixed 1G speed interface using a > 16-bit control word. Implementations of this exist where the control > word can be disabled. > > Cisco came along, took 1000base-X and augmented it to allow speeds of > 10M and 100M by symbol repetition, and changing the format of the > 16-bit control word. Otherwise, it is functionally compatible - indeed > SGMII with the control word disabled will connect with 1000base-X with > the control word disabled. I've done it several times. > > There exists 2500base-X, which is 1000base-X clocked faster, and it > seems the concensus is that it has the AN disabled - in other words, > no control word. Thank you for a nice explanation! I think that this information should be part of documentation as it could help also other people to understand differences between these modes.
