Verilink DPRI 2922 (880-503142-001) Product Manual - Manual (Page 38)

Configuring the DPRI 2922 Via the NCM 2000 Craft Interface
3-8
Verilink DPRI 2922
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. This is the recommended option for ISDN.
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.
AMI requires use of an ISDN inverted D-channel.
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) 0 db
2) -7.5 db
3) -15 db
4) -22.5 db
NDn Network Density: Use this option to specify the type of network density
enforcement to use with PRI line coding. Digital transmissions over public
switched telephone network lines cannot support long strings of zeros
(repeaters and clocking devices lose synchronization). Therefore, the
density algorithms ensure that a minimum pulse density is met to ensure
stable system timing.
Choose one of the following if using 64K AMI. Note that these options are
ignored with B8ZS line code:
None: does not insert a one. Use this option with B8ZS or a 56K channel.
Also recommended for ISDN capability.
80 zeros: inserts a one into every string of more than 80 consecutive zeros.
15 zeros: inserts a one into every string of more than 15 consecutive zeros.
12.5% & 80 zeros: inserts a one into every string of eight or more
consecutive zeros when the average density of ones fall below 12.5% or if
there are more than 80 consecutive zeros.
TR 62411: inserts a one into every string of more than 15 consecutive
zeros or when there are less than a minimum number of N ones in every
window of 8(N+1) data bits (12.5%). N can be any value from 1 to 23. This
option is the same as 12.5% + 15 zeros.
1) NONE
2) 80 zeros
3) 15 zeros
4) 12.5% & 80
zeros
5) TR 62411
NLn Network Initiated Loop: Use this option to specify if you wish to allow your
DPRI to be remotely put into a line loopback.
Yes or No
(Y/N)
Command Description Options