1. Network Concepts

2. Networks LAN WAN

3. Main Concepts n Protocol n Media n Topology

4. Peer -to -Peer Client Server Client Server Client Server

5. Client/Server Client Server

6. Bus

7. Ring

8. Star

9. Star - cable Bus - signal

10. Star - cable Ring - signal

11. Media n Coax n Twisted Pair n Fiber Optic n Wireless

12. OSI Reference Model 7Application 6Presentation 5Session 4 Transport 3 Network 2 Data Link 1 Physical

13. OSI Layers Physical –Signal encoding (voltage, amps, timing) –Connectors (BNC, RJ-45, ST) –Bit oriented Data Link –Frame oriented –Error detection –Media access control (token, CSMA/CD)

14. OSI Network –packet (datagram) oriented –Route data from network to network –Fragment and reassemble packets Transport –Reliable connection – ACK, NACK –Sequenced delivery –Flow control

15. OSI Layers Session –Logical connections Presentation –Character codes (EBCDIC vs. ASCII), encryption, Compression (nice theory, usually done in other layers) Application –Like ftp, telnet, email, www, file and printer sharing

18. IEEE vs. OSI LLC Logical Link Control MAC Media Access Control Physical Data Link Physical OSI IEEE

19. IEEE Standards n 802.2 Logical Link Control t 802.3 CSMA/CD (Ethernet) t 802.4 Token Bus t 802.5 Token Ring

20. 802.3 10Base5 10Base2 10BaseT 10BaseF 10Broad36 100BaseTX 1000BaseT

21. DIX n Digital n Intel n Xerox Ethernet

22. IEEE vs. Ethernet Terminology EthernetIEEE 802.3 StationDTE - Data Terminal Equipment Transceiver cableAUI - Attachment Unit Interface TransceiverMAU - Medium Attachment Unit ConnectorMDI - Medium Dependent Interface

23. Ethernet Frame PreambleDestination Address Source Address Length/ Type LLC/ Data Frame Check Sequence

24. Ethernet Frame PreambleDestination Address Source Address Length/ Type LLC/ Data Frame Check Sequence 64 bits of alternating ones and zeroes, for hardware synchronization, ending with two ones

25. Ethernet Frame PreambleDestination Address Source Address Length/ Type LLC/ Data Frame Check Sequence 48-bit address of station frame is being sent to

26. Ethernet Frame PreambleDestination Address Source Address Length/ Type LLC/ Data Frame Check Sequence 48-bit address of station sending the frame

27. Ethernet Frame PreambleDestination Address Source Address Length/ Type LLC/ Data Frame Check Sequence 16-bit field, length of frame in 802.3, type of frame in DIX

28. Ethernet Frame PreambleDestination Address Source Address Length/ Type LLC/ Data Frame Check Sequence 46 to 1500 bytes of data, includes LLC fields in 802.3

29. Ethernet Frame PreambleDestination Address Source Address Length/ Type LLC/ Data Frame Check Sequence 32-bit cyclic redundancy check (CRC) code

30. Ethernet Addresses n 48 bit n normally shown in HEX n e.g.: 02-60-8C-44-59-E0 n first 24 bits are obtained from IEEE by hardware manufacturers n one bit is used to distinguish unicast from multicast addresses n one bit is used to distinguish locally assigned addresses(rare) from globally assigned addresses (typical)

31. Transmission Types n Unicast - intended for one specific station n Broadcast - intended for all stations n Multicast - intended for a group of stations

32. CSMA/CD n Carrier Sense, Multiple Access with Collision Detection n Carrier sense - don't transmit if there is already a signal n Collision detection - if a collision is detected stop, wait, and retransmit

33. No Carrier

34. Transmission

36. End of Transmission

37. Transmission

38. Second Transmission

39. Collision

40. Collision detected

41. Wait

42. Repeater Hub

44. one station transmits

45. Repeater Hub signal repeated on all other ports

46. Repeater Hub end of transmission

47. Repeater Hub