=> Steps below are taking an example for PRI. One 1 B channel can be captured at a time.
=> As we do not know which B channel the call will come in on, we need check the right B-channel in real time.
=> For issues relating to call setup, you could try busying out channels, OR using Triggered PCM capture (not discussed here).
=> Same steps can we be used for FXO/FXS ports too, only change the port numbering scheme.
*** PCM capture instructions:
conf t
voice hpi capture destination flash:pcm.dat
voice hpi capture buffer 5000000
exit
>> At this point you need to figure out exactly which voice port you are on:
show call active voice brief
(http://www.cisco.com/en/US/tech/tk652/tk698/technologies_tech_note09186a008019ab88.shtml)
>> Once you have the port information then you issue the following command:
# test voice port 0/0/0:15.1 pcm-dump caplog 7 ----> assuming you are on PRI 0/0/0:15 and the 1st B-channel
>> Once you are done capturing the issue, do this to stop the capture
# test voice port 0/0/0:15.1 pcm-dump disable
conf t
no voice hpi capture destination flash:pcm.dat
no voice hpi capture buffer 5000000
>> Now do a dir flash: and you will see a file "pcm.dat" that's the file. You will need to send this file to TAC, so it can be analyzed.
>> Remember if you need to redo the call, always delete the pcm.dat file, and start again. Just so that we do not have calls multiple call info in a single PCM file.
