Here use CM-1G-D12 for example:
1.Cross-Connect 2 X CM-1G ports (Port 1 and Port2) using built-in RJ45 transceivers (T1 and T2) and short (<1 foot) copper cable (C1).
2.On both ports, remove Latency Compensation, Tx and Rx offset = 0ns
3.Average Latency for streams(64Byte, 1518Byte) is -7ns, within 10ns resolution and centered at zero.
4.This is the Cross-Connect Latency(CCL). It includes
Port internal Latency(PL): Port1 Tx and Port2 Rx queuing delays;
Transceiver Latency(TL): T1 Tx and T2 Rx transceiver delays;
Cable Latency(CL): Propagation delay of the cable C1;
CCL= PL + TL + CL