Verilink DIDCSU 2912 (880-502646-001) Product Manual User Manual

Page 48

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DIDCSU T1 Version

3-8

Verilink DIDCSU 2912 User Manual

Ln

Line Coding: Use this option to choose Alternate Mark Inversion (AMI) or

Bipolar Eight-Zero Substitution (B8ZS), as required by the type of your T1

facility.

B8ZS enables each DS0 to transmit at 64 kbit/s with unlimited zeros. This

option overrides any selected network density enforcement.

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.

1) AMI

2) B8ZS

Bn

Line Build Out: Line build-out is used to reduce the transmit signal

amplitude of the CSU.

0 db: if the repeater is between 2000 and 3000 feet from the CSU, or if you

are using a network termination device (smart jack) used by most phone

companies (most common setting).

• -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

NDn

Network Density: Use this option to specify the type of network density

enforcement. 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 56K AMI. Note that these options are

ignored by B8ZS line code:

• None: does not insert a one. Use this option with B8ZS.

• 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 falls 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 the far

end or telco to put your DIDCSU in a loopback. (Usually Yes)

Yes or No

(Y/N)

An

Alarm Declare Time (sec): Use this option to indicate how many seconds will

elapse before a message regarding a problem is displayed.

0...127

seconds

DLn

FDL Enable/PRM Enable: Facilities Data Link (FDL). The ESF

Facilities Data

Link is used to transmit performance information, error events, and

loopback controls. FDL uses 4 kbit/s of the 8K framing bandwidth on an ESF

T1 to transmit messages. This option only enables or disables FDL. The

Performance Report Message Command/Response (PRM C/R) displayed with

this option shows the current status of the PRM C/R bit. To change this

option, use F (FDL Configuration) and select Cn (PRM C/R bit). Enabling FDL

is meaningless for ports connected to an SF-framed T1.

Yes or No

(Y/N)

Command

Description

Options

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