Paradyne M/HDSL Standalone Termination Unit Hotwire 7984 - Manual (Page 66)

Testing
5-10 7984-A2-GB20-10 February 1999
Telco-Initiated Payload Loopback
The Hotwire 7984 Standalone Termination Unit supports 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.
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 payload
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