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Computer Networking

author: Jim Hogan date: 2015-01-14 transition: fade incremental: true

Research Computing and Data Management

http://github.com/brianhigh/research-computing

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Creative Commons License

Introduction

  • A 30-minute introduction
  • Some historical background
  • The purpose
  • Evolution to contemporary computer networks
  • Key technical aspects including:
    • networking topologies
    • protocols and standards
    • networking system components

Networking History

Chappe Network

Networking History

1792

Chappe Network

Chappe Telegraph

Chappe System]

Moving Along

1889

Early Networking

1943

Bell Switchboard

Enter Binary

10000000010111110111000000000001

Some Binary Basics

Recognize this number?

128.95.112.1

How about this one?

10000000010111110111000000000001

Question

Would not Morse code be considered a binary communication protocol?

Computer Networks: What's the Point?

  1. Allow a computer system/device to communicate with another computer system by exchanging data
  2. Allow humans to interact with computer systems
  3. Allow humans to interact with other humans.

Contemporary Computer Networks: Key Elements

  • Key Elements
  • Binary Operation
  • Packet Switching
  • Protocols
  • Another biggie:
    • Layered Model
  • And some other bits:
    • software and hardware components
    • network topologies
    • network speeds
    • more...

Protocols, Standards and Governing Bodies

International Telecommunications Union International Telecommunicatios Union

Internet Engineering Task Force Internet Engineering Task Force

The TCP/IP Protocol Suite

  • Embodied in documents called "RFCs" (Request For Comment)
  • Many design decisions around factors like efficiency and reliability
  • Some protocols humorously start with the word "Simple" or "Lightweight"."

Questions

How many different protocols are under the TCP/IP umbrella?

What is ICANN? IANA?

Packet Switching and Routing Metrics

Routing example

  • Hops
  • Latency
  • Congestion
  • Queuing

Resolution of Names and Addresses

  • DNS: phage.deohs.washington.edu => 128.95.230.32
  • ARP: 128.95.230.32 => 26:a5:b7:20:f0:35

Question

What were the design goals of ARPANET?

Data Flow of the Layered TCP/IP Model

TCP/IP Model

The Internet Protocol Suite Wikipedia Page

Layers, Protocols, and Encapsulation

(Not translated from the Dutch)

encapsulation

Types of Networks

  • LAN - Local Area Network

  • WAN - Wide Area Network

  • LAN - less need for routing

  • WAN - more need for routing

Topologies and the Networking Layer

Topologies

  • Mesh, Star and Tree arguably more common in this era
  • Complex networks can combine elements of several topologies

Link Layer Technologies (Ethernet Rules!)

From bus-based in the 80s

10Base2

To the familiar RJ45

RJ-45

Over copper and fiber media

copper and fiber

All standards thanks to

IEEE

Network Speeds

Familiar Speeds in Common Use:

10 Mbps - Ethernet 10BaseT - outmoded

100 Mbps - "Fast Ethernet" - still very common

1000 Mbps - "Gigabit Ethernet or 1Gbps" - typical in new devices

Faster speeds possible but expensive.

Primary Networking Devices

  • switches

  • router

  • access point

Devices may combine functions and be hard to distinguish by appearance.

Switch

Using the Network Effectively

  • network could be performance bottleneck
  • wired connection more reliable than wireless
  • read and write speed to local disk always faster
  • troubleshooting:
    • start with closest component
    • learn how to use simple tool "ping"
    • get a grip on name resolution/DNS
    • know how to determine your IP address

Networking on Computing Basics Wiki