1 / 32

OSI Seven Layer

OSI Seven Layer. 1. Physical Layer. (1). 2. Physical Layer. (2) RS-232C. 3. Physical Layer. (3) Manchester. 4. Physical Layer. (4) Differential Manchester. 0. Signal voltage changes in the middle of the bit； Signal voltage changes in the beginning of the bit

kawena
Download Presentation

OSI Seven Layer

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. OSI Seven Layer 1

  2. Physical Layer (1) 2

  3. Physical Layer (2) RS-232C 3

  4. Physical Layer (3) Manchester 4

  5. Physical Layer (4) Differential Manchester 0. Signal voltage changes in the middle of the bit； Signal voltage changes in the beginning of the bit 1. Signal voltage changes in the middle of the bit； Signal voltage do not change in the beginning Control Signal voltage do not change in the middle of the bit 5

  6. Data Link Layer MAC information: http://map-ne.com/Ethernet/vendor.html 6

  7. Network Layer Some of the Routing Protocols: • RIP • RIPv2 • OSPF • IGRP • EIGRP • IS-IS • BGP 7

  8. Network Layer Routed Protocols： • IP • IPX • Apple Talk • DecNET 8

  9. Network Layer Network Layer Address： • Hierarchical • Network Number • Host Number • Logical Address MAC Address： • Flat • Physical Address 9

  10. TCP/IP Model DOD Reference Model OSI Model 10

  11. TCP/IP Model 11

  12. TCP/IP Model IEEE 802 Standard 12

  13. TCP/IP Model IEEE 802 Standard(Cont’d) 13

  14. TCP/IP Model IEEE 802 Standard(Cont’d) http://grouper.ieee.org/groups/802/dots.html 14

  15. Summary OSIModel Functions: • Compression/Decompression • Encryption/Decryption • Connection Establishing/Terminating • Segmentation/Reassembly • Flow Control • Error Control • Addressing/Routing 15

  16. Summary OSIModel Functions: (Cont’d) • Sequencing • Encapsulation/Decapsulation • Encoding/Decoding • Multiplexing • Synchronization • Positive Acknowledgement and Retransmission (PAR) • Windowing 16

  17. Internet Protocol First Octet Rule Default Class First Octet Range Idea Subnet Mask ------ ------------- ---------- ----------- ------------------ A 0xxx xxxx 0~127 N.H.H.H 255.0.0.0 B 10xx xxxx 128~191 N.N.H.H 255.255.0.0 C 110x xxxx 192~223 N.N.N.H 255.255.255.0 D for multicast E for research 17

  18. Internet Protocol Class Networks Nodes in each network A B C 128 256 x 256 x 256 64 x 256 256 x 256 32 x 256 x 256 256 18

  19. Calss Default Host bits Maximum borrowing A 24 22 B 16 14 C 8 6 Subnet 19

  20. Subnet Example 1 172.16.40.4 255.255.255.0 10101100.00010000.00101000.00000100 11111111.11111111.11111111.00000000 AND 10101100.00010000.00101000.00000000 172 . 16 . 40 . 0 Network Number AND 0 0 0 1 0 0 0 1 0 1 1 1 • . 16 . 40 . 4 • 255 . 255 . 255 . 0 • 172 . 16 . 40 . 0 AND 20

  21. Subnet Example 2 172.16.40.4 255.255.224.0 10101100.00010000.00101000.00000100 11111111.11111111.11100000.00000000 AND 10101100.00010000.00100000.00000000 172 . 16 . 32 . 0 Network Number AND 0 0 0 1 0 0 0 1 0 1 1 1 • . 16 . 00101000 . 4 • 255 . 255 . 11100000 . 0 • 172 . 16 . 00100000 . 0 21

  22. Subnet Example 3 172.16.0.0 255.255.224.0 Continuous 0 to 1 Subnet Mask 11111111.11111111.11100000.00000000 172 . 16 .000xxxxx.xxxxxxxx .001xxxxx.xxxxxxxx .010xxxxx.xxxxxxxx .011xxxxx.xxxxxxxx .100xxxxx.xxxxxxxx .101xxxxx.xxxxxxxx .110xxxxx.xxxxxxxx .111xxxxx.xxxxxxxx Subnets 23 Valid subnets 23 -2 Total nodes in each subnet 213 Valid nodes in each subnet 213 -2 Abbreviation: 172.16.0.0/19 22

  23. Subnet Example 4 172.16.0.0 / 255.255.255.0 Continuously borrowing bits from the right Subnet Mask 11111111.11111111.11111111.00000000 172 . 16 .00000000.xxxxxxxx .00000001.xxxxxxxx .00000010.xxxxxxxx . … .11111111.xxxxxxxx Subnets 28 Total nodes in each subnet 28 172.16.0.0/24 23

  24. Subnet Network Number: The first node of each network Broadcast address: The last node of each network 172.16.0.0/20 172.16.32.0 172.16.47.255 172.16.0.0/24 172.16.15.0 172.16.15.255 172.16.0.0/28 172.16.15.64 172.16.15.79 24

  25. Subnet Class C 25

  26. Subnet Best IP Saving • borrowing bits = left-over bits 26

  27. Subnet 27

  28. Subnet IP 10.128.32.64, Find its broadcast IP /8 10.255.255.255 /17 10.128.127.255 /25 10.128.32.127 /10 10.191.255.255 /18 10.128.63.255 /26 10.128.32.127 /11 10.159.255.255 /19 10.128.63.255 /27 10.128.32.95 /12 10.143.255.255 /20 10.128.47.255 /28 10.128.32.79 /13 10.135.255.255 /21 10.128.39.255 /29 10.128.32.71 /14 10.131.255.255 /22 10.128.35.255 /30 10.128.32.67 /15 10.129.255.255 /23 10.128.33.255 /16 10.128.255.255 /24 10.128.32.255 28

  29. Subnet Find the broadcast address of the following IP： 128.1.2.3/29 128.1.2.7 16.65.30.1/20 16.65.31.255 128.5.6.7/28 128.5.6.15 16.65.60.1/19 16.65.63.255 128.4.5.6/30 128.4.5.7 16.65.140.1/18 16.65.191.255 128.3.4.5/26 128.3.4.63 16.65.100.1/17 16.65.127.255 128.10.15.20/27 128.10.15.31 16.65.1.1/16 16.65.255.255 128.5.160.3/23 128.5.161.255 16.65.0.0/15 16.65.255.255 128.6.7.10/25 128.6.7.127 16.65.3.4/14 16.67.255.255 128.7.6.4/22 128.7.7.255 16.65.100.200/13 16.71.255.255 128.6.27.8/21 128.6.31.255 16.65.128.255/12 16.79.255.255 29

  30. Subnet • IP and Subnet Mask work together to define the neighborhood(network range) of that IP • Router uses routing table to make path decision • Routing table records the relationship of network number and the router’s interface (port); not the IP to the port • Intermediate routers forward packets based on their destination network number, not the destination IP • The final router uses IP to get the MAC of the destination host, then uses the destination MAC to deliver the packet (within a frame) 30

  31. Private IP 10.0.0.0 1 x 224 = 224IP(10.0.0.0~10.255.255) 172.16~31.0.0 16 x 216 = 220 IP(172.16.0.0~172.31.255.255) 192.168.0.0 256 x 28 = 224IP (192.168.0.0~192.168.255.255) 31

  32. Summary When IP and its subnet mask are known, the following can be determined: ·The subnet number of this subnet ·The broadcast address of this subnet ·The range of this subnet ·The maximum subnets allowed by this mask ·The number of hosts in this subnet ·Borrowing bits and total network bits (/number) http://www.johnscloset.net/cgi/dictionary.pl?Netmask 32

More Related