Loop fault or short circuit can occur indoors as well?
Rule of thumb is that a loop fault is indoors or right at the customer end. This is because in order to cause engaged tone the insulation must be below 1Kohm resistance. In the network you would expect service problems before things got that bad as resistance to other lines would come in to play. Of course rules of thumb are not always accurate and for example paper insulated cables and spades through cables can cause big insulation fails quickly.
Edited by partial (Fri 30-Nov-18 21:29:04)