Paradyne Hotwire 7974, User Manual

Page: 89 / 165

Testing
6-19
7970-A2-GB20-00 August 1999
Telco-Initiated Payload Loopback
The Hotwire 7974 and 7984 Standalone Termination Units support payload
loopback as specified in AT&T TR 54016 and ANSI T1.403. A Telco-initiated
payload loopback loops the received signal on the DSX-1 interface back to the
DSX-1 interface. Framing, CRC, and FDL bits are regenerated at the point of the
loopback, and BPVs are removed.
CAP
DSL
Port DSX-1
Port
CAP T1
LIU
Framer Framer Transceiver
99-16253
All Ones
Telco
Telco-Initiated Remote Line Loopback
If Remote Telco Loopback is enabled, a Telco-initiated line loopback loops
received data at the remote unit and passes it back to the Telco through the local
unit.
The following figure shows the data flow for a remote Telco-initiated line
loopback.
CAP
DSX-1
Port
CAP T1
LIU
Framer Framer Transceiver
98-16109
CAP CAP T1
LIU
Framer Framer Transceiver
Telco
Local Remote
DSX-1
Port
AIS
DSL