The Signaling System No. 7 (SS7) switch designated as control switch for circuits in the both-way circuit group. For the same circuits, the other switch is referred to as the slave. On detecting glare, the control switch proceeds to complete the call for which it has already sent an initial address message (IAM. ) The IAM received from the slave is discarded. The call being processed by the slave is backed off and the switch path released. A release message is not sent.