This attribute indicates which DS1 tributaries are being looped
back, or if the DS3 line is being looped back. Each value listed
indicates a loopback request has been made. When a loopback
deactivation command has been sent to the far end, the
corresponding value will be removed from the list.
Description of bits:
notused0(0)
n1(1)
n2(2)
n3(3)
n4(4)
n5(5)
n6(6)
n7(7)
n8(8)
n9(9)
n10(10)
n11(11)
n12(12)
n13(13)
n14(14)
n15(15)
n16(16)
n17(17)
n18(18)
n19(19)
n20(20)
n21(21)
n22(22)
n23(23)
n24(24)
n25(25)
n26(26)
n27(27)
n28(28)
notused29(29)
notused30(30)
ds3Line(31)