Sniffer for ExpressTalk

[johnmcneely]

I am setting up a VoIP exhibit in a telephone museum. My plan is to use ExpressTalk on two PCs connected together via Ethernet (hopefully a crossover cable between them will be enough). On one PC I had hoped to run both ExpressTalk and a Voip or TCP/IP Sniffer that I could open on a second monitor connected to that PC. That way when I make a SIP call dialing the IP address of the second PC also with ExpressTalk running, viewers of the exhibit would be able to see some representation of the packets moving between the two ExpressTalk clients. I think I remember that ExporessTalk supports a trace program but that is after-the-fact and not in realtime. Can you recommend a freely downloadable program that will display traffic across the TCP/IP connection between these two PCs and display that in a window I could display on the second monitor? Thank you.