Problem: Unanswered inbound calls continue to ring forever, even after caller's hang-up/disconnect.
Symptoms: Inbound call triggers (i) audible ringtone; (ii) flashing red line key; (iii) caller-id display; and (iv) answer/reject key display. If unanswered, audible ringtone times out (after e.g., 20 seconds), but remaining alerts continue pulsating indefinitely. Only picking up the receiver or selecting either the answer or the reject key interrupts the continuous cycle.
This behavior occurs intermittently with two different SIP carriers, Callcentric and Vestalink.
Any assistance would be appreciated!