Understanding Skype
According to Kurose and Ross, Skype is P2P.
According the IMC 2012 paper you read this week, Skype is P2P for 2-way conferences, and server-based for larger conferences.
Which one is true?

1. Download and install Skype and Wireshark.

2. Skype with a partner(s) and try to determine how the Skype infrastructure looks today. Look at the Wireshark traces on all the clients.

-What is the architecture? Does it use Azure?
-Does voice differ from video?
-Does the size of the video conference matter?
-What protocols are being used?
-Where are the servers? How many servers are used?
-Does the video rate change based on the available bandwidth? Use the bandwidth shaping tool from last week to see the effect.
-Can you understand the video overlay? (Skype -> Window -> Technical call info)

Useful commands:
Wireshark filter: “ip.addr==xxx.xxx.xxx.xxx”
Wireshark -> Statistics -> Conversations -> Sort by bytes to find important flows
Wireshark -> Statistics -> IO graph to see input/output on the wire
maxmind.com to look up IP address ownership and location
“traceroute xxx.xxx.xxx.xxx” to see the intermediate routers