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.