Question 1
A telecom operator is deploying a new metro OTN ring. The acceptance test plan requires a full suite of tests to be performed on each commissioned node before it is integrated into the live network. The tests must verify the integrity of both the client-side interfaces and the internal switching fabric of the node.
The field engineer needs to perform a test that validates the data path from a client-side input port, through the ODUk cross-connect fabric, and back out to a different client-side output port on the SAME node without requiring any external test equipment or remote node loopbacks. Which commissioning test procedure should be performed to meet this requirement?
Answer and explanation
Correct answer: D
This is the correct and comprehensive procedure. First, an ODUk cross-connection is created to route the signal from the input port's timeslot to the output port's timeslot, which explicitly tests the switching fabric. Second, an inward (terminal) loopback is activated on the output port. This directs the signal that has traversed the fabric back into the tributary board's receiver. By sending a signal into the input port (from a test set or just by monitoring for errors on an active client signal), the engineer can verify the entire path shown in the diagram, confirming the functionality of both tributary cards and the cross-connect fabric.
