The feature provides ability to measure and provide statistics to allow reporting on voice and video quality for VoIP and teleconferencing (A/V) applications. A sampled deployment is shown in Figure: Voice/video monitoring deployment example . Although a distributed model is shown, a hub-and spoke model, with AA-ISA deployed only on one side of the traffic flow, is also supported.
Because of network-based AA, the operator has an ability to monitor voice, video, teleconferencing applications for an AA subscriber regardless of the type of that subscriber (a residential subscriber vs. a user of a business VPN service). AA-ISA monitors UDP/RTP/RTCP/SDP headers for each initiated call/application session (sampling may be provided – although, it is expected that a sampling rate is smaller than that of TCP-applications because of the nature of the voice/video applications – longer lasting and smaller number of sessions/calls per subscriber). AA ISA gathers statistics and computes MOS-scores/R-factor results per each call/ application session. At the end of a call (/application session closure), AA-ISA sends the statistics and computed scores to a Cflowd collector (the Cflowd infrastructure was introduced for TCP-performance but modified to carry voice/video specific data is used). The collector summarizes and presents the results to the operator/end user.