LTPH-UM-1234-01Product Description

Table 2. Front Panel Status Indicator LED

LED

Description

Flashing Red about

Indicates an HDSL Cyclic Redundancy Check (CRC) error has

once per second

occurred between the HDU-409 and the upstream module.

Flashing Red rapidly

Indicates an HDSL CRC error has occurred between the

 

HDU-409 and the downstream module.

Flashing Yellow about

Indicates a Network Doubler Unit (NDU) loopback is in effect in

once per second

the HDU-409 towards the network. This tests the integrity of the

 

upstream span.

Flashing Yellow

Indicates a Customer Doubler Unit (CDU) loopback is in effect in

rapidly

the HDU-409 towards the customer. This tests the integrity of the

 

downstream span.

Flashing Green about

Indicates synchronization is being attempted between the

once per second

HDU-409 and the upstream (network) module.

Flashing Green rapidly

Indicates synchronization is being attempted between the

 

HDU-409 and the downstream (customer) module.

Steady Yellow

Indicates the HDSL margin is less than the margin threshold

 

provisioned for the circuit.

Steady Green

Indicates HDSL frame synchronization has been achieved

 

between the HDU-409 and both the upstream and downstream

 

modules.

HDU-409 Lists 1, 2, and 3

April 30, 2003

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