This CoriantTypesFreq value (in MHz, default 0, not applicable to SFP+ pluggables) sets the receive laser frequency for the coherent optical channel (och-os) on the line side of a pluggable transceiver independently of the transmit frequency; a value of 0 means the receiver uses the same frequency as the transmitter. An administrator configures this separately from the transmit frequency only on interfaces where the receive local-oscillator laser can be tuned independently, which matters for certain flexible-grid or asymmetric coherent configurations. For example, leaving this at the default of 0 on och-os keeps the simple case where transmit and receive share one tuned laser, while setting a distinct value would only be needed for specialized asymmetric-frequency deployments.