???? Class 1-Protocols, Architecture and Transmission Media

1
????Class 1-Protocols, Architecture and
Transmission Media

• ????
• ???
• 2001/09/26

2
Presentation Outlines

• Network Classifications
• Network Devices
• Network Software
• Network Topologies
• Network Protocols
• Switching Techniques
• Group Discussion

3
Network Classification in terms of transmission
technology

• Switch (Inter-media) Network
• Circuit-Switched Network
• Message-Switched Network
• Packet-Switched Network
• Virtual Packet-Switched Network
• Broadcast (non-inter-media) Network
• LAN Ethernet 10BASE5 and 10BASE2
• Packet Radio Network
• Satellite Network

4
Network classification in term of scale

• Local Area Network (LAN)
• Ethernet, Ether-switch
• Token Ring, Token Bus
• ATM LAN, Wireless LAN
• Metropolitan Area Network
• DQDB
• Wide Area Network
• ISDN, B-ISDN, Internet

5
Network Devices

• Repeater electronically repeating (????/?????)
  (layer 1)
• Bridge only to connect LANs with different/some
  protocol (????????/?????)(layer 2)
• Router Connect different Network (LAN, MAN,
  WAN) and routing protocol transformation (layer
  3)
• Gateway Connect different Network (WAN-to-WAN)
  and protocol transformation (layer 3 or layer
  4-7)
• Wireless Devices wireless Hubs for LAN and
  Mobile communication systems

6
Network Software

• Telnet
• FTP
• Email
• WWW
• Teleshopping (SET-Secure Electronic
  Transactions??????)
• ??????????????????????????SET??????RSA?????????(Pu
  blic Key)??????(Cryptography)???,?????????????????
  ??????
• Network Game
• Video-on-Demand(????)
• Video-Conference(????)
• Point-of-Sale(POS) accounting

7
Network Topologies

• Point-to-point
• Multipoint Broadcast
• Switched Network
• Internet

(please referred as page 34 Figure 2.1)
8
Network Protocols

• What is a Protocol ?
• A communication language between one-to-one or
  among many computers in hardware or software.
• Why standardization ? (next slide)
• Functions (pp.35-44)
• Encapsulation
• Segmentation and reassembly
• Connection control (pp.38 Figure 2.3)
• Ordered delivery
• Flow control
• Error control
• Addressing (pp. 41 Figure 2.4) and addressing
  modes (pp. 42 Table 2.1)
• Multiplexing
• Transmission services

9
Why standardization
Standard protocol
10
Three Layer Protocol Model
Application
Application
Application protocol
Transport
Transport
Transport protocol
Network Access
Network Access
Communications Network
Network access protocol
Network access protocol
A simplified layer model
11
Why Layering

• Discussion
• Design separate layers to handle different
  function, and collect similar functions into the
  same layer
• Maintain errors are easier to be located, each
  layer boundaries with its upper and lower layer
  only
• Replace allow changes without affecting other
  layers
• software engineering issues
• Principles Used in Defining the OSI layers
• (pp. 45 Table 2.2)

12
Open System Interconnection (OSI)

• Developed by International Organization for
  Standardization.
• A reference model for current and future
  protocols
• Layers Descriptions (three layer model ? OSI)
• Network access ? Physical, Data link and Network
  layers
• Transport ? Transport and Session layers
• Application ? Presentation and Application layers
• OSI layer on network equipments (next slide)

13
OSI Reference layers
14
Transmission Control Protocol/Internet Protocol
(TCP/IP)
Application
(pp.59 Application protocols by using TCP/IP as
platform)
Socket Interface
connection operations end-to-end connection
maintained, flow/error control and connection
resource managements
TCP
IP
Packet operations addressing/routing, p-t-p
link management and network resource managements
Network access
Subnet Hardware and Firmware
Physical
(OSI v.s. TCP/IP pp.22 Figure 1.11)
15
OSI v.s. TCP/IP
16
Protocol Data Units (PDUs) Segment/Reassembly
Application data (application PDU)
Transport header
Transport header
Transport SDU
Transport SDU
Transport PDU
Transport PDU
Network PDU
Network PDU
Network SDU
Network SDU
Network header
Network header
17
Why add Header and Tailor

• Addressing (next slide)
• Synchronization Intra-Connection and
  Inter-Connection synchronization
• Flow and Error Control (Quality of Service)
• Other controls packetization information

18
Addressing Concepts
19
Address Modes
Destination Network Address System Address Port/SAP Address
Unicast Individual Individual Individual
Individual Individual Group
Multicast Individual All Group
All All Group
Individual Individual All
Broadcast Individual All All
All All All
20
Switching Techniques

• Circuit Switch
• Message Switch
• Packet Switch
• Virtual Packet Switch

21
Group Discussion