1 Answers
In telecommunications, a call collision is one of two things:
Glare can sometimes be experienced as trying to make a call out on a PBX, and instead being connected to an incoming call. This can happen at home too, if a call out is made at the exact second that a call is about to start ringing in.
Multi-line hunting attempts to avoid glare by selecting circuits in opposite preference order so the highest numbered line, which is last choice for incoming calls, is first choice for outgoing calls, like so:
With PRI circuits, the channel selection sequence is specified when the circuit is provisioned. Common practice is to have the PBX use descending channel selection, and the carrier to use ascending. Glare is not common on PRI circuits because the signalling is so fast, however it is not impossible. The users will not experience a connection to an unexpected call , because glare causes protocol errors that generally prevent any sort of successful connection. Instead, one or both of the call attempts might fail, and ideally an error would appear in the logs. Glare is quite rare on PRI circuits, and can be difficult to troubleshoot.