This MIB module describes all variations of the symmetric DSL line interfaces. The structure of this module resembles and maintains consistency with the ADSL-LINE-MIB, ADSL-DMT-LINE-MIB, CISCO-ADSL-DMT-LINE-MIB, and CISCO-ADSL-CAP-LINE-MIB. Observe that the tables in this module do not necessarily extend the tables defined by the these mibs. Currently, only those tables that contain configuration information extend the profile tables defined by the above modules. This allows the management client to define DSL configuration profiles that apply across all DSL modems, independent of the technology being utilized by the modem. *** DEFINITIONS *** ATTENUATION Attenuation is a decrease in the strength of a signal over the length of a cable. CODING VIOLATION A coding violation occurs when the incoming signal exhibits a CRC anomaly. DOWNSTREAM The flow of data in the direction from the ATU-C to ATU-R. ERRORED SECOND A second with one or more coding violations or one or more incoming defects (e.g., LOS or LOSQ). LINE RATE The total data rate supported by a line. Observe that the payload rate is equal the line rate for the earliest implementations of SDSL. However, the payload rate maybe less than the line rate for future implementations. LOSS OF SYNC DEFECT A Loss of Sync Defect is defined as 3 consecutive received frames which contain one or more errors in the framing bits. A Loss of Sync Defect shall be cleared when at least 2 consecutive received frames contain no errors in the framing bits. LOSS OF SYNC FAILURE A LOSW Failure is defined as at least 2 consecutive seconds of LOSW Defect. The LOSW Failure should be cleared when the LOSW defect is absent for 20 seconds or less. (i.e. clear within 20 seconds ). MARGIN (also referred to as 'SNR margin') The difference between the SNR of the received signal and the SNR required to provide a BER of 10E-7. SEVERELY ERRORED SECOND A one second interval during which or more LOSW or CV defects are declared. UNAVAILABLE SECOND A Unavailable Second is defined as a one second interval during which LOSW Failure ( at least 2 seconds of LOSW Defect ). UPSTREAM The flow of data in the direction from the ATU-R to ATU-C. *** ABBREVIATIONS, ACRONYMS, AND SYMBOLS *** ADSL - Asymmetric Digital Subscriber Line. ATM - Asynchronous Transfer Mode. BER - Bit Error Ratio. CV - Coding Violation. DSL - Digital Subscriber Line. ES - Errored Second. LOS - Loss Of Sync. LOSQ - Loss Of Signal Quality. LOSW - Loss of Sync Word Failure PSD - Power Spectral Density. SES - Severely Errored Second. SNR - Signal-to-Noise Ratio. STM - Synchronous Transfer Mode. STU-C - SDSL Transceiver Unit, Central Office end. STU-R - ADSL Transceiver Unit, Remote terminal end. UAS - UnAvailable Second.