T 3.7 Failure of the PBX due to operating errors

In addition to technical failures due to defective components, power failures, or sabotage, there is also a series of additional circumstances that may lead to the failure of a PBX system or other telecommunication equipment. For example, due to the generally wide scope of functions of a PBX system, undesired functions may be triggered if the PBX system is operated incorrectly. A failure may be caused by insufficiently qualified maintenance personnel configuring the PBX incorrectly, for example. If alarm signals are ignored or if abnormal operating behaviour is not detected, malfunctions may occur. Incorrect or thoughtless actions during simple routine repair work may also cause a PBX system to fail.

Since there are far-reaching conceptional and technological differences between traditional PBX systems and VoIP solutions, a switch to VoIP often requires comprehensive retraining of the personnel. In addition, in-depth knowledge of IP network technology is also needed. If the PBX system is operated improperly due to insufficient knowledge, this may cause more than only failures of the telecommunication infrastructure when connected to IP networks. If the VoIP media stream is to be transmitted over a data network workstation which computers and servers are connected to, a misconfiguration may cause the failure of the entire data network.

Examples:

• While configuring the VoIP PBX system, an inadequate compression algorithm using too much bandwidth and overloading the data network was selected for the transmission of the voice data. The result was that it was impossible to work productively on the workstation computers and impossible to remotely configure the VoIP system. The administrator responsible for the VoIP PBX system suspected the problem to be a misconfiguration of the network, which a different administrator was responsible for, and did not take any action. Only after analysing the network activity was the problem discovered and eliminated. Even though the actual correction of the error in the configuration only took a few minutes, operations were significantly disrupted for over an hour.
• Due to the deliberate or accidental misconfiguration of a PBX system, individual ports may be configured in such a way that they are no longer available from the outside, through changing of the extension, for example. If the free line signal is signalled to the outside in the event of such a failure, it may take some time until such a malfunction is detected.