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I would like to analyse packets sent by skype from my computer. Particularly I am interested in packets that transmit messages.

With what filter I can see this packets on wireshark. I know that dropbox is using it's own protocol for synchronizing file lists between clients, so I am wondering is there a specific protocol that skype is using.

Salvador Dali
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1 Answers1

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First off, Wireshark doesn't have explicit Skype support yet so you won't get pretty decodes. If you're wiling to compile from source, you can build it in.

Second, Skype encrypts everything so there isn't much to look at once you get the packets.

Third, it doesn't use a predictable port unless egress to the network is restricted to only allow TCP/80 or TCP/443, so you'll have to find them in the swarm of normal traffic. But that should be easy if you've properly isolated your network connections.

sysadmin1138
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    Although I would note that skype will also use UDP if it does not detect NAT/Firewalls in the way. – prateek61 Oct 25 '12 at 20:24
  • I am aware that skype encrypts all the outputs. I was just interested what protocol does it use to send messages and how I can look at them in wireshark – Salvador Dali Oct 25 '12 at 20:26
  • You cannot look into the encrytped traffic that easy. Otherwise encription would be pointless and Wireshark will only give you encrypted traffic that will look pretty much like garbage. – Christopher Perrin Oct 25 '12 at 22:34