Appendix A. Hdsl2 Loopback - ADTRAN T200 H2TU-R Installation And Maintenance Manual

HDSL2 MAINTENANCE MODES
This Appendix describes operation of the HDSL2
system with regard to detection of in-band and ESF
facility data link loopback codes.
Upon deactivation of a loopback, the HDSL2 system
will synchronize automatically.
Loopback Process Description
In general, the loopback process for the HDSL2
system elements is modeled on the corresponding
DS1 system process. Specifically, the H2TU-C
loopback is similar to an Intelligent Office Repeater
loopback, and the H2TU-R loopbacks are similar to a
T1 Smart Jack loopback.
61222026L7-5B
Appendix A
HDSL2 Loopbacks
The unit can detect the loopback activation or
deactivation code sequence only if an error rate of
1E -03 or better is present.
Loopback Control Codes
A summary of network and customer control
sequences is given in Table A-1.
In all control code sequences presented, the
in-band codes are shown left-most bit transmitted
first, and the ESF data link codes with right-most
bit transmitted first.
Section 61222026L7-5, Issue 2
NOTE
A-1