1. R. Smith - University of St Thomas - Minnesota
Course Notes
9/18/2018
QMCS Class Today
Homework/Exam
Circuit/Message/Packet Switching
Internet Architecture
DNS and distributed processing
After the exam:
Chapter 4 Homework
Finish Chapter 5: TFTP, Florida Case Study
9/18/2018
R. Smith - University of St Thomas - Minnesota
© Copyright 2005, Richard E. Smith. All rights reserved.

2. R. Smith - University of St Thomas - Minnesota
Homework/Exam
Status on Homework 4?
Exam next Tuesday
Topics and concepts through Last Week
This week may provide “examples” instead of “concepts”
Exam Format
Open book/open notes
Some calculations
Use 210 ~ 103 estimates in calculations
May use SIMPLE calculators, but probably not necessary
9/18/2018
R. Smith - University of St Thomas - Minnesota

3. R. Smith - University of St Thomas - Minnesota
Exam Topics
Chapter 2
Given 1D, 2D, or 3D data, what network speeds do we need?
Given a network speed (Hz or bits/second) how much can we send?
Chapter 3
Trade-offs between centralized and distributed
Centralized vs client/server vs peer-to-peer
Database organization: centralized, replicated, partitioned
Packet networking (PDF slides)
What’s essential in a packet for reliability and performance
Chapter 5
7 ISO layers; relation to TCP/IP layers
Relation between software layers and packet format
Role of IP vs TCP vs UDP
Relation between IP and “Link” layer (routing and addresses)
May use DNS as an example of above concepts (Ch. 4)
9/18/2018
R. Smith - University of St Thomas - Minnesota

4. R. Smith - University of St Thomas - Minnesota
Questions ? ?
Chapter 2: network speeds, data sizes
Chapter 3:
Types of distributed applications
Types of distributed databases
Why pick one over another?
Packet Networking
Essential elements of a packet
What goals can we achieve with simple packet protocols
Chapter 5:
ISO layers & TCP/IP layers
Layers vs packet formats
“Important” contents of TCP/UDP/IP packets
Link layer packet formats
9/18/2018
R. Smith - University of St Thomas - Minnesota

5. Circuit/Message/Packet Switching
What’s the difference?
Which came first?
9/18/2018
R. Smith - University of St Thomas - Minnesota

6. Internet Architecture (alphabet soup)CO
CPE
ISP
NAP (kind of obsolete)
NSP (OK)
POP
Questions
Is the Internet peer-to-peer, hierarchical, or what?
What’s the phone company stuff got to do with this?
9/18/2018
R. Smith - University of St Thomas - Minnesota

7. DNS and distributed processing
What is DNS for?
What do the names look like?
Why do we call DNS a distributed database?
What’s the deal with forwarding vs proxying a query?
9/18/2018
R. Smith - University of St Thomas - Minnesota

8. R. Smith - University of St Thomas - Minnesota
TFTP – page 131
How it hooks into the system
Packet format
Protocol ‘ladder diagram’
9/18/2018
R. Smith - University of St Thomas - Minnesota

9. R. Smith - University of St Thomas - Minnesota
Florida Case Study
Kind of old fashioned, but illustrates a point
“Why give up what we know and have good support for?”
9/18/2018
R. Smith - University of St Thomas - Minnesota

10. R. Smith - University of St Thomas - Minnesota
Chapter 4 Homework
-1, -6, -7, -10, -11, -12
9/18/2018
R. Smith - University of St Thomas - Minnesota

11. Creative Commons License
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9/18/2018
R. Smith - University of St Thomas - Minnesota