Yeah I think SyncE is what telecom RANs use to get within 5g reqs on timing. White Rabbit operates like 1588 + SyncE + a compensation model for the fiber link.

Yeah I think SyncE is what telecom RANs use to get within 5g reqs on timing. White Rabbit operates like 1588 + SyncE + a compensation model for the fiber link. It's pretty slick. It does need L2-L1 coordination but the ethernet MAC usually has no idea of what's happening on the L1 (it speaks "medium independent interface" or *MII). The CERN people warn against using Base-T since the PHY needs to do pretty complex signal processing which would likely destroy the syntonization. They then use basic fiber links, but 100g, 400g+ have a gearbox and DSP and FEC in the way.