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Transition from Armed to Loopup State
A specific HDSL unit moves from the armed state into the loopup state when commanded by an inband control code sequence. There is a unique
As part of the loopup activation process, each of the HDSL units will respond with a loopup identification signature that consists of a burst of bit errors in the looped payload. Upon receiving three or more seconds of the specific activation code sequence, the addressed HDSL unit will respond as follows:
•Loopback of the received payload data for five seconds.
•A burst of bit errors in the looped payload.
•Continued loopback of the received payload.
The number of bit errors returned in this loopup identification signature is specific to each HDSL unit as follows:
•HLXC – 231 bit errors
•HRX – 10 bit errors
•HLXR – 20 bit errors
Note: The bit errors inserted for the loopup identification signature may occur in the frame bit position as well as the payload in a looped SF or ESF framed data signal.
Transition from Armed to Disarmed State
The standard
The ESF data link disarming sequence used for CPE smartjack loopdown is a command for all HDSL units to go from the armed state into the disarmed state. The ESF disarm sequence is repeated four times.
All HDSL units go from the armed state into the disarmed state when the default
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