1. Networked Graphics Building Networked Virtual Environments and Networked Games Chapter 3: Overview of the Internet

2. THE INTERNET

3. Application Transport Network Link Physical DHCP, DIS, DNS, FTP, HTTP, IMAP, RTP, SMTP, SSH, Telnet TCP, UDP, RSVP IP, ICMP, IGMP Ethernet, 802.11, ADSL copper wires, fibre-optic cable, radio waves

4. Message Segment Packet Frame Application Data Transpo rt Header Network Header Link Header Link Footer

8. TRANSPORT LAYER

9. Bits0 15 16 31 0-31Source PortDestination Port 32-63LengthChecksum 64+Data

10. Transport Network Link Transport Network Link Application Source Port = Port1 Destination Port = Port2 Destination Port = Port3

13. Transport Network Link Transport Network Link Application Source Port = 1901 Destination Port = 15001 narok (128.16.13.118 ) seychelles (128.16.3.52 ) Destination Port = 15000 Source Port = 1220

14. Transport Network Link Application Msg i Msg i-2Msg i-1… Data Heade r Buffer Segment

15. Bits0 15 16 31 0-31Source PortDestination Port 32-63Sequence Number 64-95Acknowledgement Number 96-127 Data Offset Not Used FlagsReceive Window 128- 159 ChecksumUrgent Pointer 160- 191 Options (Optional) 160+ 192+, 224+, etc. Data

16. Transport Data Heade r Send Buffer Receive Buffer Byte Expected Received Data Sent Data Start Byte Start Byte + MSS Sequence Number = Start Byte Acknowledgement Number = Byte Expected Unsent Data

17. Header Sequence Number = M Transport Send Buffer Acknow- ledged Last Acknowledged = M Next Sequence Number = N Unsent To Send Data Transport Receive Buffer Received Expected = N Just Received Transport Send Buffer Acknowledged Last Acknowledged = N Unsent Header Acknowledgement Number = N

19. Transport Network Link Transport Network Link Application Source Port = 1995 Destination Port = 15001 narok (128.16.13.118 ) seychelles (128.16.3.52 ) Destination Port = 15000 Source Port = 1234

21. Seq # = 100 Data Host AHost B Seq # = 200 Data Seq # = 300 Data Ack # = 200 Data Ack # = 200 Data Seq # = 200 Data Ack # = 400 Data

22. Seq # = 100 Data Seq # = 200 Data Ack # = 200 Data Seq # = 200 Data Timeout Host AHost B

23. Seq # = 100 Data Seq # = 200 Data Seq # = 300 Data Ack # = 200 Data Ack # = 400 Data Ack # = 300 Data Host AHost B

24. SYN Seq # = N SYN, ACK Ack # = N+1,Seq # = M ACK Ack # = M+1,Seq # = N+1 Host AHost B

25. FIN ACK FIN ACK Wait, then close Host AHost B

28. Time Rate (bytes/s) 10K 20K 30K

29. NETWORK LAYER

30. Router Route Table IP Packet

31. Bits0 15 16 31 0-31 VersionHeader Length Type of Service Total Length 32-63Identification Flags Fragment Offset 64-95Time to LiveProtocolHeader Checksum 96-127 Data Offset Not Used FlagsReceive Window 128- 159 Source Address Destination Address 160- 191 Options (Optional) Bits0 15 16 31 0-31 VersionHeader Length Type of Service Total Length 32-63Identification Flags Fragment Offset 64-95Time to LiveProtocolHeader Checksum 96-127Source Address 128- 159 Destination Address 160- 191 Options (Optional) 160+ 192+, 224+, etc. Data

37. Bits0 15 16 31 160- 191 TypeCodeChecksum 192- 223 IDSequence

38. LINK AND PHYSICAL LAYER

41. Bits0 15 16 31 0-31 VersionHeader Length Type of Service Total Length 32-63Identification Flags Fragment Offset 64-95Time to LiveProtocolHeader Checksum 96-127 Data Offset Not Used FlagsReceive Window Bits0 15 16 31 0-31Destination MAC Address … 32-63… Destination MAC AddressSource MAC Address … 64-95…Source MAC Address 96-127EtherTypeData … …CRC Checksum

42. OTHER NETWORK FACILITIES

46. SUMMARY