Wireshark Voice Codec
Wireshark Rtp Stream Analysis
Git submodule initgit submodule updateDecoding BCCHFirst let's take a look on the Broadcast channel.We start wireshark at the beginning (see for more info), so we can analyze the decoded messages.Next start grgsmdecode with the following options: grgsmdecode -c vfcall6a725d174g5Kc1EF00BAB3BAC7002.cfile -s $((100000000/174)) -a 725 -m BCCH -t 0-c is specifying the cfile formatted file-s specifies the sample rate of the capture, which is dependent on the hardware. The file we are working on was captured with a sample rate of 100e6, but with a decimation of 174. That's why we perform the division 100000000/174, and put in inside the $((.)) so that it is evaluated by your command line before passing it to the program. If you have no decimation, you don't have to do this.-a 725 tells the app the ARFCN of the capture-m BCCH is the channel type we are using, BCCH in our case-t 0 specifies the timeslotAfter running, look for the Immediate Assignments in Wireshark.