This reports the current raw APS protocol byte value transmitted on the protection channel for CDL interfaces, the transmit-side counterpart to cApsStatusCdlApsBytesRcv, again serving the role that cApsStatusK1K2Trans serves for SONET. Comparing this transmitted value against what the far end reports receiving (via its own equivalent received-bytes object) helps confirm the CDL protection channel's signaling is actually reaching the peer correctly. For example, a persistent mismatch between what this element transmits here and what the far end reports as received would point to a problem in the CDL link itself rather than in either device's APS logic.