Verilink T1 ESF CSU (34-00309.B) Product Manual - Manual (Page 18)

6 I NSTALLATION AND C ONFIGURATION
NOTICE: Position SW1-1 is not enabled for use.
E Q L B O Positions SW1-2, SW1-3, and SW1-4 set the EQ LBO (line
build out) transmit signal value towards the customer equipment.
The value should match the cable length from the EQ port to the
attached equipment. The default is 0 to 133 feet (AAA).
E q u ip m en t L o op Position SW1-5 sets equipment loopback functions. When the
switch is set to Enabled (B), the unit is placed into an equipment
loopback where the equipment receives all the data it sends. The
unit remains in equipment loopback until the switch is set to
Disabled (A). The unit sends an unframed all ones pattern to the
network.
N etw o rk L o op Position SW1-6 sets network loopback functions. NET LOOP
can be set to Auto or Manual. Auto (A) enables the unit to
respond to network loop requests. Setting the switch to Manual
(B) forces the unit into a manual network loopback. During loop,
the unit sends an unframed all ones pattern to the equipment. It
responds to inband CSU loop (1-in-5 pattern) and unloop (1-in-3
pattern), ESF out-of-band line loopback/payload loopback, and
loop up/loop down codes, and responds to the universal
loopdown code even if the switch is in the "Manual" position.
N etw o rk L B O Positions SW1-7 and SW1-8 set the network line build out
signal level transmitted towards the T1 facility. The default
output level is 0 dB (AA). Change the signal level to -7.5 dB,
-15 dB, or -22.5 dB as necessary. The telco can provide the
proper setting. If unsure of the setting, leave it at 0 dB.