Paradyne 8747 사용자 설명서
Testing
8-12
8700-A2-GB20-00
April 2000
Telco-Initiated Payload Loopback
The Hotwire 8747 and 8777 Termination Units support payload loopback as
specified in AT&T TR 54016 and ANSI T1.403. A Telco-initiated line 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. DSL time slots mapped to the DSX-1 port are sent all ones.
specified in AT&T TR 54016 and ANSI T1.403. A Telco-initiated line 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. DSL time slots mapped to the DSX-1 port are sent all ones.
CAP
DSL
Port
Port
DSX-1
Port
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.
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 payload
loopback.
loopback.
CAP
DSX-1
Port
Port
CAP
T1
LIU
Framer
Framer
Transceiver
99-16626
CAP
CAP
T1
LIU
Framer
Framer
Transceiver
Telco
Local
Remote
DSX-1
Port
Port
AIS
DSL
Telco-Initiated Remote Line Loopback cannot be used in cross-connect mode.