Trouble

Trouble, in telephone terminology, is any problem with the operation of a switching machine or other facility. Trouble can be caused by a bug or other design problem, or it can be caused by transient phenomena like dirty contacts, wiring issues, false grounds, or short circuits.

When trouble occurs, some aspect of a switching machine or facility may be impaired. The degree of the impairment depends on the severity of the trouble, and on how redundant the system is. Telephone switches are designed in such a way that any single circuit failure will not drastically impair the entire machine, however trouble in the power room or a break in a critical outside cable could have far reaching consequences for a larger geographic area

Trouble is detected by routine tests, and error detection mechanisms in telephone switches. It is repaired by maintenance staff, either manually correcting the problem, or replacing a failed component with a new one.