Media Stop Time VSA in CDRs
An accurate portrayal of a call’s media stop time is important for billing accuracy. Calls are often terminated well after the media has stopped flowing for such reasons as network or equipment peculiarities.
Media Stop Time VSAs
To record the actual media stop time, the Oracle Communications Session Border Controller writes the following four VSAs in CDR Stop Records:
Acme-Flow-Calling-Media-Stop-Time_FS1
Acme-Flow-Called-Media-Stop-Time_FS1
Acme-Flow-Calling-Media-Stop-Time_FS2
Acme-Flow-Called-Media-Stop-Time_FS2
These VSAs correspond to:
- calling side’s media stop time - stream 1
- called side’s media stop time - stream 1
- calling side’s media stop time - stream 2
- called side’s media stop time - stream 2
Media Stop Time Calculation
The granularity of the time at which the Oracle Communications Session Border Controller’s checks for media stream idleness, the actual media stop time, as inserted into a CDR is accurate to between 0 and +10 seconds.
In the following diagram, media idleness monitoring is checked in 10 second time frames. Labeled time measurements are as follows:
Tc—Time between most recent idleness sample end and end-of-call time
Tm—2 complete idleness windows
Te—Time into the idleness window in which the call’s media stopped. This is also the error amount of the recorded media stop time.
Ti—The actual time between the end of media and the end of call.
![The Media Idleness Monitoring Timeline image shows a timeline with Tc, Tm, Te, and Ti timeframes, defined above and used for media idleness monitoring. The Media Idleness Monitoring Timeline image shows a timeline with Tc, Tm, Te, and Ti timeframes, defined above and used for media idleness monitoring.](img/media-stop-time-vsa.png)
Tm and Tc are known. The Oracle Communications Session Border Controller also knows that the media ended between 20 and 30 seconds, but the actual time, 10- Te into the frame is unknown. Thus, the time recorded in the CDR is quantized up to the end of the media stop frame at 30 seconds. This time, as written to the CDR, must be interpreted with possible error of 0 ≤ Te < 10 seconds.