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In this example, the packet dump contains only one VoIP call. Like the previousexample, this packet dump is from my Cisco 7940 VoIP phone using SIP (10.220.0.160) tomy Asterisk server (10.220.0.1). If multiple calls were present, this screen would show eachcall. Since there is only one call, we’ll select that one. Once chosen, the Player button shouldbecome available. Upon selecting the Player button, you should see something similar toFigure 10.6.Figure 10.6 Wireshark RTP PlayerUnderstanding and Taking Advantage of VoIP Protocols • Chapter 10 319Select the Decode button.The Wireshark RTP player should then appear, looking somethinglike the one in Figure 10.7.Figure 10.7 Decoded Wireshark RTP PlayerFrom here, select the stream to listen to and then click Play. It’s as easy as that.The onlydisadvantage at this time is that you can’t save the audio out to a file.That’ll probably changeas Wireshark supports more VoIP options.This method also has a nice “Graph” feature, which breaks down the call into a nice,simple format.To use this, we perform the same steps to get to the Player button, but ratherthan selecting Player, we click Graph. Clicking the Graph button should generate a screensimilar to that in Figure 10.8.