Glare is a signaling condition where a switch attempts to seize a two-way trunk for an outbound call at the exact same moment the remote switch seizes it for an inbound call. Because both ends are trying to use the same circuit, the call setup fails. Telecom systems resolve this by assigning a priority hierarchy, where one switch yields to the other and selects a different available trunk.
Heard on the job
We're seeing too much glare on the T1, so let's configure the PBX to hunt channels top-down while the telco hunts bottom-up.
Insider tip
The standard fix for glare on bidirectional trunks is configuring one side to allocate channels in ascending order and the other in descending order.
Also heard as
- call collision