Dropped calls are calls which were technically cut off before the call parties had finished their conversation. The dropped-call ratio (DCR) KPI is defined as the fraction of dropped calls over all established calls.
The problem: How to reliably detect call drops? What are the technical reasons for premature termination of calls? Qrystal eliminates the need for tedious configuration of proprietary SIP reason headers (RFC 3326), by learning from actual user behavior.
Users experiencing a call drop will often try to re-establish the call. The second call between two parties in short succession is referred to as ‘redial call’. These call pairs are analyzed to learn the set of SIP reason headers that have a high likelihood for redialing. In this way, call drop reasons are continuously analyzed and automatically learned by Qrystal.