Hi Don,
Quick question: How do you save to .wav files? That option isn't available is
the release of development version of Wireshark. Please paste the version string.
If you're saving .au files then it's a conversion of the detected compression
law to 16bit PCM. The code is from Sun, based on the CCITT expansion tables.
That should tell you what levels there are.
Thanx,
Jaap
Don McKinnon - AST wrote:
We are troubleshooting an IP PBX that is having echo issues with a PSTN
Gateway. We're using wireshark to capture the packets and have exported
the G.711 audio to a wav file, then we're using Adobe Audition to review
the wav files. However we have questions related to the G.711 levels
and the wav conversion as we do not have a method of inserting a known
G.711 signal for calibration:
When exporting is performed is the G.711 Mu-Law digital full scale (DFS)
equal to the wav file DFS we see with Adobe Audition?
If so, then G.711 0 dBm0 would be 3.14 dB below DFS, but is this -3.14
dB peak or the rms value (we are thinking peak since it's related to DFS)?
Hopefully we are asking the correct questions here. If anyone can
assist with this issue it would be greatly appreciated.
Don
