Test Access Copper  Fibre


When a customers reports a fault on a DSLAM provided service it is critical to respond quickly and maintain customer satisfaction and loyalty. Testing the DSLAM port is easier to say than do, most DSLAM vendors offer  "SELT, DELT and MELT" (SDM) as a solution, at a cost. The DSLAM is an extremely clever device and can produce statistics for everything, the actual problem may be masked by the amount of data, but worse still may not be able to identify the fault.

"SELT, DELT and MELT" only works on faults where the DSL connection to the customer is working. If the connection is not established then SDM is useless. It will report the failure to connect, but can't tell you if it is the DSLAM Port. a faulty DSLAM card, the customers modem or a fault on the line.

Giving this functionality to a service desk operator is a waste of time and leads to the customer going to another service provider.

SELT = Single Ended Line Test    DELT = Double Ended Line Test     MELT = Metallic Line Test

The only true way to check a line is by sending an engineer to site with the correct tools or using remote diagnostics to switch into the circuit and review the results of the test equipment . Using one of these options allows a full Copper Line check to be carried out, both to the customers line and to the DSLAM port.

An engineer may need to visit several sites to resolve the issue, or travel between 2 points until it is resolved. This delays the repair and becomes costly in terms of Truck Rolls and wages.

Accessing the line circuit remotely and having intelligent tools to test automatically is the cheapest option. The level of knowledge required by service desk staff is also reduced as the right test equipment will diagnose the fault and report back with a simple to read status screen.


SELT, MELT, DELT compared to TAM / TASM

Fault Process



Fibre network faults are likely to have a much bigger impact on a larger number of customers. A single fault on a fibre close to the content generating equipment could affect 128 customers. As the network spans out towards the customers this may decrease but could still impact more than one customer. As broadband services become ever more popular and being online is as essentail as having electricity it is important to restore service as quickly as possible.

A new set of tools to assist in service fault locating and fault diagnostics are now available for the fibre network. See an overview here and the tools here