Projekt
user's (Bart) phone rings, its SIP-client gives out the message 180 (Ringing, a call), then the user
takes the call, the SIP-client gives out the message 200 (OK), the first SIP-client sends the second
signal ACK (acknowledgement) and further is going the transfer of a vocal stream under protocol RTP
(Real-time Transport Protocol) begins. When conversation is ended also one of users hangs up a
receiver, the SIP-client sends signal BYE.
Monitoring
Forthermore, we need to monitor or control our-made connection. For this purpose we use an
application from Malden Electronics - VoIP Monitor Professional. This is a software tool for
non-intrusive assessment of speech quality and measurement of RTP/RTCP traffic parameters in
VoIP networks. VoIP Monitor analyses the RTP traffic to produce real-time useful statistical
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data and predictions of speech quality across a single call or a number of calls
annaabi.ee 
