Troubleshooting and Maintenance
5-27
9161-A2-GH30-20
September 1997
Digital Loopbacks
A Digital Loopback loops the digital voice signal received from the T1 interface
back to the same interface, just before reaching the D-to-A converter on the voice
port.
496-15200
to: T1 Interface
Digital Loopback
CODEC
D to A
Converter
The following tests cannot be running when a digital loopback test is initiated:
Analog Loopback, DRS or Quiet Test Tone on the same port
Analog Loopbacks
An Analog Loopback loops the analog voice signal received from the T1 interface
back to the same interface, after passing through the Digital-to-Analog converter
and Analog-to-Digital converter on the voice port.
496-15201
to: T1 Interface
Analog Loopback
CODEC
D to A
Converter
The following tests cannot be running when an Analog Loopback test is initiated:
DRS or Quiet Test Tone, or Digital or Line Loopback on the same port