Verilink DCSU 2911 (880-502647-001) Product Manual - Manual (Page 29)

DCSU T1 Craft Interface
Verilink DCSU 2911 User Manual 3-7
Table 3-4 DCSU Configuration Menu Command Keys
Command Description Options
In In Service: This option places the port in service. Yes or No
(Y/N)
Fn Frame Format: Choose SF (Superframe) or ESF (Extended Superframe Format) as
dictated by what your installation supports. ESF is recommended. Select SF for
installations not supporting ESF.
SF provides traffic signaling and framing.
ESF provides cyclic redundancy check, performance monitoring, data checking,
and link bits (Facility Data Link, or FDL). The chart below shows which
combinations of framing formats at the equipment and network ports are valid:
Equipment Network Valid Option
ESF ESF Yes
SF SF Yes
SF ESF Yes
ESF SF No
1) SF
2) ESF
Ln Line Coding: Use this option to choose Alternate Mark Inversion (AMI) or
Bipolar Eight-Zero Substitution (B8ZS) as dictated by your T1 facility.
B8ZS is a protocol that replaces eight consecutive zero bits with two intentional
bipolar violations (BPVs) that are not counted as errors by the B8ZS equipment.
B8ZS enables each DS0 to transmit at 64 kbit/s with unlimited zeros. This
option overrides any selected network density enforcement.
AMI is a T1 signal in which successive ones (pulses) alternate in polarity and in
which zeros (spaces) are of zero amplitude. AMI is the original T1 line format
that does not support long strings of zeros. Normally, this option is used in
conjunction with the network density enforcement option.
If the T1 facility experiences pattern sensitive errors or constant dribbling
errors, verify that the unit is not mis-optioned for AMI. The intentional errors
inserted by B8ZS equipment cannot be decoded by the AMI equipment.
1) AMI
2) B8ZS
Bn Line Build Out: Line Build Out is the signal strength used by the CSU and is
calculated by considering the length of the cable connecting the first line
repeater and the CSU. It is the db loss inserted to compensate for transmitting
levels to first repeaters when no network interface is involved. Choose one of
the following options:
0 db: if the repeater is between 2000 and 3000 feet from the CSU, or if you are
using a network interface unit (smart jack) used by most phone companies.
-7.5 db: if the repeater is between 1000 and 1999 feet from the CSU.
-15 db: if the repeater is between 250 and 999 feet from the CSU.
-22.5 db: if the repeater is between 0 and 249 feet from the CSU.
1) 0db
2) -7.5db
3) -15db
4) -22.5db