This INTEGER value (in ps/nm, default 45000) sets the high end of the chromatic dispersion search range that the coherent optical channel (och-os) on the line side of a pluggable transceiver's coherent receiver scans when acquiring dispersion compensation for the incoming signal. An administrator narrows this bound, together with the corresponding low bound, to match the expected dispersion of a known fiber route and speed up signal acquisition after a restart or reconfiguration. For example, lowering this high bound on och-os for a short regional span would prevent the receiver from unnecessarily searching dispersion values appropriate only to long-haul routes.