alb analog loopback

    ascii american standard code for information interchange

    bert bit error rate tester

    c control signal

    cpss control packet switching system

    cts clear to send

    dcc direct connect card

    dcd data carrier detect

    dce data communications equipment

    dcm direct connect module

    dgnd digital ground

    dnic digital network interface circuit

    dpm dnic processor module

    dsr data set ready

    dte data termination equipment

    dtr data terminal ready

    dtu data termination unit

    emc electromagnetic compatibility

    fcc federal communications commission

    fgnd frame ground

    fic facility interface code

    hcm high capacity multiplexing

    i indicate signal

    led light emitting diode

    n/a not applicable

    nmti node management terminal interface

    rdl remote digital loopback

    ren ringer equivalence number

    ri ring indicator

    rts request to send

    rr ring return

    rxd receive data

    scr signal carrier ready

    sct signal carrier transmit

    selv safe extra low voltage

    sgnd signal ground

    srm subrate merger

    tnv telecommunications network voltage

    txd transmit data

    usoc universal service order code

    xclk external clock