Line build out (LBO) is loss inserted by the CSU
in order to meet the 15 to 22.5 dB loss requirement
of the premises remote-end section. Selected so
that (phone company loss) + (cable length loss) +
(line build out) is greater that 15dB but less than
22.5 dB.
buildOut0 means insert 0 dB.
buildOut7p5 means insert 7.5 dB.
buildOut15 means insert 15 dB.