Specifications

4-8 Peripheral Cards and Components
Chapter 4 - Maintenance and Troubleshooting
XTS-IP - Installation Manual December 2005
CO Line Card Functions
The Loop Start CO Interface Board provides loop start line interface from the Public Telephone
Network to provide ringing and loop start flash.
PRIB/BRIB ISDN and T1IB are digital CO interface boards.
Table 4-5: Loop Start CO Interface Board (LCOBC)
Problem Possible Solutions
8 Loop Start CO lines on the
system are not working …
 Check wiring.
 Try a replacement LCOBC to identify if
card is defective.
 Check programming.
CO Line(s) are not ringing … Check CO Line Ring Assignment in
programming.
Noise or Crosstalk on the line. (CO
Line checks fine at demarcation
point with system isolated) …
 Check whether CO lines are bundled too
tightly.
 Try a replacement LCOBC to identify if
card is defective.
CO Button not working …
 Check wiring.
 Check programming of CO lines.
Telephone side tone is high …
 Check LCOB Loop Length programming.
Table 4-6: PRI/BRI ISDN and T1
Problem Possible Solutions
Popping, crackling, dropped calls,
or one-way transmission …
Verify the following settings and
connections:
 The LD1 on the MPB is lit.
 The clock source switch on the LMU1 is
set correctly for the external clock
source being used.
 The clock cables are connected
correctly.
 The clock switches on the BRIB/PRIB/T1
are set correctly.