1. Internet Protocols Midterm is two weeks away  Break is Saturday 

3. Fetching a Web Page www.si.umich.edu Home computer The Internet

4. Fetching a Web Page www.si.umich.edu Home computer The Internet MichNet Modem

7. Simplified Internet Topology Hosts Routers/Switches Access links Backbone links

9. Conceptual Layering of Internet Protocols/Services Internet Protocol (IP) Subnets User Datagram Protocol (UDP) Transmission Control Protocol (TCP) HyperText Transport Protocol (HTTP) Application Real-time Transport Protocol (RTP) Application Layer Transport Layer Network Layer Data Link and Physical Layer Internet Protocol (IP) Last week’s topic Today’s topic Each layer provides services to the layer above, and utilizes service provided by the layer below

10. Comparing the OSI and TCP/IP Reference Models Data Link Physical Network Transport Presentation Session Application Host-to- Network Transport Application Internet

11. Questions

18. Questions

26. Fetching A Web Page www.si.umich.edu Home computer MichNet Modem 207.75.186.1 198.108.3.5 141.211.0.9 141.211.203.32 c-ccb2 router c-ugli router

27. TRACERT SI.UMICH.EDU 1 * Request timed out. 2 140 ms 207.75.186.1 3 140 ms f-umbin.c-ccb2.umnet.umich.edu [198.108.3.5] 4 240 ms f-backbone.c-ugli.umnet.umich.edu [141.211.0.9] 5 141 ms bart.si.umich.edu [141.211.203.32] www.si.umich.edu Home computer MichNet Modem 207.75.186.1 198.108.3.5 141.211.0.9 141.211.203.32 c-ccb2 router c-ugli router

30. IP over Voice Gateway Public telephone network Internet Computer w/modem    Computer w/modem

31. Voice over IP Gateway Public telephone network Internet IP telephone or computer running VoIP software Plain old telephone   

33. IP over Voice Gateway Public telephone network Internet Computer w/modem    Computer w/modem

34. Voice over IP Gateway Public telephone network Internet IP telephone or computer running VoIP software Plain old telephone   