Fdl [ansi | att | none – ADTRAN 1000R Series User Manual
Page 700
Command Reference Guide
T1 Interface Configuration Command Set
61200510L1-35E
Copyright © 2005 ADTRAN
700
fdl [ansi | att | none]
Use the fdl command to configure the format for the facility data link (FDL) channel on the T1 circuit.
FDL channels are only available on point-to-point circuits. Use the no form of this command to return to
the default value.
Syntax Description
ansi
Configures the FDL for ANSI T1.403 standard.
att
Configures the FDL for AT&T TR 54016 standard.
none
Disables FDL on this circuit.
Default Values
By default, the FDL is configured for ansi.
Applicable Platforms
This command applies to the NetVanta 1000R, 3000, 4000, and 5000 and Total Access 900 Series units.
Command History
Release 1.1
Command was introduced.
Functional Notes
T1 circuits using ESF framing format (specified using the framing command) reserve 12 bits as a data link
communication channel, referred to as the FDL, between the equipment on either end of the circuit. The
FDL allows the transmission of trouble flags such as the Yellow Alarm signal. Refer to
for related information.
Usage Examples
The following example disables the FDL channel for the T1 circuit:
(config)#interface t1 1/1
(config-t1 1/1)#fdl none