VOIPFUTURE announced a "call correlation process matches VoIP signaling sessions with the media streams belonging to the session and essentially attaches a subscriber ID to call quality. The patent pending correlation mechanism matches multiple media streams including those from early media, like ring tones or tariff announcements, codec changes and network address translation (NAT) impaired sources to the correct signaling session"
Michael Krueger (pictured), Head of R&D said: “The correlation engine is designed to work in decomposed environments such as IMS and LTE where network equipment may be spread across multiple geographical locations .. The challenge of any voice quality SLA is to match voice media quality with phone numbers. Phone numbers, subscriber IDs, routes, destination etc. are the common data for service contracts”
See "Communication Service Providers Can Implement Voice Quality SLA" - here.