01 intro
- 1. Computer Networks CR320 ¢ Professor Douglas Lyon ¢ Lyon@docjava.com ¢ Fairfield University ¢ http://www.docjava.com
- 2. Course Text ¢ Javafor Programmers ¢ Available from: – http://www.docjava.com
- 3. Grading ¢ Midterm: 1/3 ¢ Homework: 1/3 ¢ Final: 1/3 ¢ Midterm and Final – Take home!
- 4. Email ¢ Please send me an e-mail asking to be placed on the CR320 List ¢ E-mail: lyon@docjava.com
- 5. Pre-reqs ¢ You should have CS232 and MA 172 ¢ OR permission of the instructor ¢ You need a working knowledge of Java!
- 6. DATA COMMUNICATION NETWORKS Communication networks switched unswitched
- 7. DATA COMMUNICATION NETWORKS Switched Circuit Switched Packet Switched
- 8. DATA COMMUNICATION NETWORKS Unswitched(broadcast nets) packet radio satellite local Packet switched nets are store and forward nets.
- 9. DATA COMMUNICATION NETWORKS ckt switched nets have dedicated communication paths (i.e. telephone) For example: node net station A Broadcast Comm. Net can be WAN, the media is unshared
- 10. DATA COMMUNICATION NETWORKS Dish LAN EXAMPLES:
- 11. DATA COMMUNICATION NETWORKS Ethernet with a bus topology:
- 12. DATA COMMUNICATION NETWORKS Ring topology net: Note: No switching nodes ,media is shared in LAN For packet radio,every station can hear every other, the media is shared so this is a LAN technology
- 13. Computer Communications Architecture The Three Layer Model Application run on computer which use networks ¢ network layer - xchange of data between computer and network ¢ transport layer - error detection and correction ¢ application layer - file xfer etc.
- 14. Transmission Terminology ANSI Defs: – simplex - one direction only – half-duplex - two-way but not at the same time. – full-duplex - simultaneous two way transmission
- 15. Transmission Terminology ¢CCITT – CCITT vs ANSI – simplex = half-duplex – duplex = full-duplex ¢CCITT = international telegraph and telephone consultive committee
- 16. ISO-OSI Model ¢ISO= International Standards Organization ¢OSI = Open Systems Interconnection ¢OSI Model = a 7 layer model used to describe most networks today
- 17. 1. Physical Layer ¢Thisis a physical connection between machines. BITS
- 18. 2. Data Link Layer ¢Provides reliable transfer of information across the physical links. FRAMES/Packets or DLPDU
- 20. 4. Transport Layer ¢errorrecovery and flow control
- 21. 5. Session Layer ¢Controlfor communication, close and open connections
- 22. 6. Presentation Layer ¢Data formatting and character code conversion
- 23. 7. Application Layer ¢file transfer, ¢virtual terminals, electronic mail ¢etc..