The MIB for voice and Nx64 over ATM Trunking applications. The following lists the abbreviations used in this MIB: AAL ATM Adaption Layer AIS Alarm Indication Signal CID Channel Identifier DSP Digital Signal Processing DTMF Dual Tone Multi Frequency FCS Frame Check Sequence TDM Time Division Multiplexing PVC Permanent Virtual Circuit RAI Remote Alarm Indication RDI Remote Defect Indication SID Silence Insertion Descriptor SVC Switched Virtual Circuit VAD Voice Activity Detection VBD Voice Band Data VC Virtual Circuit