VoQM service measures the quality of Multimedia Services in a network by simulating a client behaviour. VoQM service registers to an application server and performs basic call functionalities like a client. With using this simulation technique, VoQM service collects :

• Registration Request Delay (RRD): Time between sending first REGISTER message and getting 200-OK.

• Session Request Delay (SRD): Time between sending INVITE message and getting 180-Ringing.

• Session Establishment Rate (SER): Time between sending INVITE message and getting 200-OK.

• Session Duration Time (SDT): Talking time.

• Session Disconnect Delay (SDD): Time between sending BYE message and getting 200-OK.

After this collecting process is completed, VoQM service calculates:

• Answer Seizure Rate (ASR): Ratio of successful calls to calls which were responded by other side

• Answer to Bid Ratio (ABR): Ratio of successful calls to all calls

• Network Efficiency Rate (NER): Ratio of calls which were responded by other side to all calls

• Call Setup Time (CST): Time between sending INVITE message and getting 180-Ringing.

Figure 1 - On-net Call Test with using VoQM service

Figure 2 - Off-net Call Test with using VoQM service