You can extract an RTP stream from Wireshark (used to be called Ethereal) and convert to audio to play with windows media player or cool edit. It's really handy for audio quality issues.
To extract RTP audio using Wireshark:
- Select a UDP packet.
- Decode as RTP by selecting: Tools-> Decode As -> Transport -> RTP -> Apply
- Invoke RTP stream analysis by selecting Tools-> Statistics -> RTP Streams -> Analyze. This will bring up the analysis window, with each stream under a different tab.
- Streams may be saved separately or mixed as .au files (8000 HZ, 8-bit, mono PCM) by selecting the Save Payload button. This brings up the Save window, where it is possible to select Forward, Reverse, or Both for the stream(s) to save. You must specify a directory in which to save and a file name.
- The resulting .au audio file can then be heard on a system with a sound card with any audio player such as Windows Media Player or CoolEdit.