Introduction to Computer Networking EE432/532 Spring 2004

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Introduction to Computer Networking
EE432/532Spring 2004
Ken Burst, Ph.D. P.E.
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Introduction

• Introduction to Computer Networks and Internets,
  3rd Edition, Douglas E. Comer
• After Completing this Course You Will Have
  Mastered the Concepts and Terminology of Computer
  Networking and Internets at a High Level
• You Will Be Prepared for In Depth Study and
  Investigation of this Topic

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Syllabus

• Syllabus Handout and Discussion

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Overview

• A Computer Is a Tool
• The Abilities of that Tool Are Tremendously
  Enhanced When Connected to Other Computers
• This is Networking
• Examples
• Banking, Distance Learning, Information at Your
  Fingertips, Shopping, Stock Trading

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Introduction

• Introduction (Chapter 1)
• Motivation and Tools (Chapter 2)
• Transmission Media (Chapter 4)
• Local Async Communicatioins (Chapter 5)

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Ping Demo
PING hyperion.lhl.uab.edu (138.26.152.111) 56
data bytes 64 bytes from 138.26.152.111
icmp_seq0 ttl247 time26.2 ms 64 bytes from
138.26.152.111 icmp_seq1 ttl247 time67.7
ms 64 bytes from 138.26.152.111 icmp_seq2
ttl247 time93.6 ms 64 bytes from
138.26.152.111 icmp_seq3 ttl247 time27.5
ms --- hyperion.lhl.uab.edu ping statistics
--- 4 packets transmitted, 4 packets received, 0
packet loss round-trip min/avg/max
26.2/53.7/93.6 ms
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Traceroute Demo
1 24-240-115-1.hsacorp.net (24.240.115.1)
11.128 ms 11.313 ms 10.742 ms 2
24-216-185-1.hsacorp.net (24.216.185.1) 10.579
ms 12.107 ms 11.924 ms 3 552.Hssi4-0-0.GW2.ATL
1.ALTER.NET (157.130.77.97) 19.173 ms 19.214 ms
20.640 ms 4 105.ATM2-0.XR2.ATL1.ALTER.NET
(146.188.232.70) 20.811 ms 19.221 ms 23.315
ms 5 194.ATM5-0.GW5.ATL1.ALTER.NET
(146.188.233.1) 19.223 ms 19.435 ms 20.227 ms
6 deltacom-gw.customer.alter.net (157.130.74.50)
26.266 ms 24.060 ms 22.750 ms 7 10.52.1.10
(10.52.1.10) 32.636 ms 22.694 ms 21.307 ms 8
ATM11-0.2.BHM.deltacom.net (209.192.87.82)
47.662 ms 24.269 ms 39.923 ms 9
uab.gw-customer.deltacom.net (209.192.87.210)
51.465 ms 37.974 ms 27.251 ms 10
Electreon.dpo.uab.edu (138.26.1.1) 28.205 ms
29.541 ms 29.088 ms 11 hyperion.lhl.uab.edu
(138.26.152.111) 28.749 ms 34.539 ms 25.592 ms
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Concepts TerminologyYou Will Need to Know

• LAN
• WAN
• Modem
• Router
• Bridge
• Switch
• Connectionless

• Encapsulation
• TCP/IP
• MAC Address
• IP Address
• DNS
• URL
• Client/Server

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Concepts TerminologyYou Will Need to Know

• NIC
• Packet
• ATM
• Frame Relay
• PVC
• SVC
• Firewall

• ftp
• http
• html
• Java
• RPC
• MIB
• API

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Data Transmission

• Transmission Media (Chapter 4)
• Local Asynchronous Communications (Chapter 5)
• Carriers, Modulation, and Modems (Chapter 6)

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Transmission Media

• Copper Wires
• Glass Fiber
• Radio
• Satellites (GEO, LEO, LEO Satellite Arrays)
• Microwave
• Infrared
• Wireless (802.11a, b, g)

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Twisted Pair Wiring

• Examples
• Telephone Transmission Lines (ADSL, HDSL)
• Ethernet Cat5 Cabling (100 BaseT Ethernet)
• T1 Transmission Lines (Used to Interconnect
  Routers for ISDN)

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Coaxial Cable

• Cable Television (Cable Modems)
• T3 Transmission lines (Used to Interconnect
  Routers and Switches)

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Fiber Optic Cables

• Interconnecting Telephony Switches
• Interconnecting Core Routers and Switches
• Cable Television
• Fiber To The Home

Single Mode Fiber
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Satellite Communication
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Satelite Communication

• Video Distribution
• Weather Imaging
• Worldwide Communications

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Local Asynchronous Communications (RS-232)

• Local A short distance
• Asynchronous No coordination between the sender
  and receiver concerning when transmissions start
  and stop
• RS-232 A popular local async standard

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Data Transmission involves Energy Transfer Across
Media

• Data is encoded into some form of Energy on one
  end of the media
• Energy is transmitted through the media
• Energy is decoded back into data on the other
  side of the media
• Examples
• Light across fiber
• Voltage across twisted pair

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RS-232

• Start bit
• Stop bit
• Baud rate
• Character oriented
• NRZ

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RS-232 Full Duplex 3 Wire Circuit

• DCE Data Circuit terminating Equipment
• DTE Data Terminal Equipment
• Crossover needed for DTE-DTE or DCE-DCE

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Voltage Pulse

• Rise time
• Fall time
• Sample time should be near the center

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Nyquist Sampling Theorem

• Data rate 2B for 2 symbols (0 and 1)
• Data rate 2Blog2K Where K
  is the number of symbols

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Shannon's Theorem

• Channel Capacity Blog2(1 S/N)
• Example Voice Telephone Line
• B 3000 cycles/sec
• S/N 30 dB 1000
• Channel Capacity 3000log2(1 1000)
• log2(x) ln(x)/ln(2) gtgtgt log2(1001) 9.97
• Channel Capacity 30,000 bits/sec

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Bandwidth vs Data Rate

• Data Rate is limited by Bandwidth
• Encoding can increase Data Rate as shown by
  Nyquist's Theorem
• However there is a limit as shown by Shannon's
  Theorem