This parameter defines the signal pattern for inband loopback activation and deactivation: csu Applicable only for SF (D4) and ESF line types Defined in AT&T TR54016 and ANSI T1.403. Loop-up pattern - 00001 detected for at least 5 seconds Loop-down pattern - 001 detected for at least 5 seconds fdlLine Applicable only for ESF line type. Defined in ANSI T1.403. Loop-up pattern - 00001110 11111111 Loop-down pattern - 00111000 11111111 or 00100100 11111111 (universal deactivate) fdlNetwork Applicable only for ESF line type. Defined in ANSI T1.403. Loop-up pattern - 00010010 11111111 Loop-down pattern - 00100100 11111111 niuFac1 Applicable for framed and unframed line types. Define in Telcordia (Bellcore) TR-TSY-0312. Loop-up pattern - 0011 Loop-down pattern - 0111 niuFac2 Applicable for framed and unframed line types. Define in Telcordia (Bellcore) TR-TSY-0312. Loop-up pattern - 00011 Loop-down pattern - 00111 program User configurable loop-up and loop-down patterns. The patterns and their length are set in: dsx1InbandLoopUpCode dsx1InbandLoopUpLength dsx1InbandLoopDownCode dsx1InbandLoopDownLength The specified pattern is applicable only when the value of dsx1CsuLoop is local(2) or remote(4). This parameter is applicable only for T1.