Lecture about networking related to electronics.

1. Computer Communication Networks
Introduction to Internet
Engr. Abbas Abbasi

2. Course Info
 Refer to course outline file available at course website

3. What is Internet???
 Write down name of five hardware parts attached to
Internet…
 Can you think of some software used to access Internet?
 Why do we want to access Internet? What services are
provided by it?
 Nuts and bolts description
 Service description

4. Chapter 1: Introduction
Our goal:
Overview:
 get “feel” and terminology
 what’s the Internet
 more depth, detail later in
 what’s a protocol?
course
 approach:
 use Internet as example
 network edge
 network core
 access net, physical media
 Internet/ISP structure
 performance: loss, delay
 protocol layers, service models
 network modeling

5. Chapter 1: roadmap
1.1 What is the Internet?
1.2 Network edge
1.3 Network core
Network access and physical media
Internet structure and ISPs
1.4 Delay & loss in packet-switched networks
1.5 Protocol layers, service models
1.6 Networks under attack: security (covered in Chap. 8)
1.7 History

6. What’s the Internet: “nuts and bolts” view
 millions of connected computing devices:
hosts = end systems
 running network apps (email,Web, telephone,
banking, time, updates, …)
 communication links
 fiber, copper, radio, satellite
router
server
workstation
mobile
local ISP
 transmission rate = bandwidth
 routers: forward packets (chunks of data)
regional ISP
 search engines: "crawl" the Web, sorting
Web sites by key words into huge data
bases (e.g., Google).
 security systems: monitor the Web traffic
for malicious activities.
company
network

7. Nuts and Bolts of Internet

8. What’s the Internet: “nuts and bolts” view
 protocols control sending, receiving
of msgs
 e.g., TCP, IP, HTTP, FTP, PPP
 Internet: “network of networks”
 loosely hierarchical
 public Internet versus private intranet
router
server
workstation
mobile
local ISP
regional ISP
 Internet standards
 RFC: Request for comments
 IETF: Internet Engineering Task Force
company
network

9. What’s the Internet: a service view
 communication infrastructure
enables distributed applications:
 Web, email, games, e-commerce, file
sharing
 communication services provided
to apps:
 Connectionless unreliable
 connection-oriented reliable

10. What’s a protocol?
human protocols:
 “what’s the time?”
 “I have a question”
 introductions
… specific msgs sent
… specific actions taken when
msgs received, or other
events
network protocols:
 machines rather than humans
 all communication activity in
Internet governed by
protocols
protocols define format, order of
msgs sent and received among
network entities, and actions
taken on msg transmission, receipt

11. What’s a protocol?
a human protocol and a computer network protocol:
Assalam o Alaikum
TCP connection
request
Wa’alaikum Salam
TCP connection
response
Got the
time?
Get http://www.edmodo.com
2:00
<file>
time
Q: Other human protocols?

12. Important Terms used in Lec 1
 Host or End System
 Communication Link
 Transmission rate
 Packet
 Packet Switching
 Route or Path
 Router
 Link Layer Switch
 ISP
 Protocol
 TCP
 IP
 RFC
 Distributed Application
 API