This MIB module defines objects to manage Converged Data Link (CDL). CDL provides OAM&P (Operation, Administration, Maintenance and Provisioning) in Ethernet packet-based optical networks without a SONET/SDH layer. The CDL functionality can be divided into the following categories: APS/Defect Indications: The CDL frame carries defect indication bits and provides signalling mechanism support for automatic protection switching. Message Channel: The message channel is used to carry control (e.g. routing, signalling) and management traffic. Packet-by-packet multiplexing of multiple data flows: CDL uses one or two octets to identify the elementary packet stream that this packet belongs to. This allows more than one elementary packet stream to share the bandwidth on a CDL enabled interface. This MIB defines objects to manage Defect Indications and the Packet-by-packet Multiplexing feature. The CDL Message channel is modeled as a separate interface and should be controlled using the IF-MIB and other MIBs for managing IP. This MIB does not provide a mechanism to manage the CDL message channel. APS configuration and monitoring can be done using the CISCO-APS-MIB and CISCO-APS-EXT-MIB.