Paradyne U8777, 8779 manual Telco-Initiated Tests, Telco-Initiated Line Loopback

8. Testing

Telco-Initiated Tests

Hotwire 8777 Termination Units support Telco-initiated tests, as shown in the following table.

Activation and	Line	Payload	Remote Line
Deactivation	Loopback	Loopback	Loopback
In-Band Signal	Supported	Not Applicable	Not Supported
Bit-Oriented	Supported	Supported	Supported
Message-Oriented	Not Applicable	Not Supported	Not Applicable

Telco-Initiated Line Loopback

Hotwire 8777 Termination Units support line loopback, as specified in AT&T TR 54016, AT&T TR 62411, and ANSI T1.403. A Telco-Initiated Line Loopback loops the received signal on the DSX-1 interface back to the DSX-1 interface without modification. Framing, CRC, and FDL bits are returned unaltered, and no BPVs or other line coding errors are removed. DSL time slots mapped to the DSX-1 port are sent all ones.

DSL

Port All Ones

CAP CAP

Transceiver Framer

T1

Framer

LIU

DSX-1 Telco Port

99-16252

Telco-Initiated Payload Loopback

Hotwire 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.

DSL

Port All Ones

CAP CAP

Transceiver Framer

T1
LIU	DSX-1	Telco
	Port
Framer
	99-16253

8700-A2-GB20-40 May 2002 8-11