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Fundamentals  of  Computer  Networks  ECE  478/578  

Spring  2013  

Introduc)on  

Course  Outline  (1)  

•  Fundamentals  of  Computer  Networks  (ECE  478/578)  

•  Course  Schedule:  Tuesday  &  Thursday,    – 8:00am  –  9:15am  

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Course  Outline  (2)  

•  Website:    acl.ece.arizona.edu/classes/ece478    

•  Instructor  –  Youssif  Alnashif,  Ph.D.  – Office:  356  P/N  ECE  Building  –  Email:  alnashif@ece.arizona.edu  –  Instructor  Office  Hours:    

Tuesdays      9:15am  –  10.15am  Thursdays  2:30pm  –  3:30pm  

Course  Outline  (3)  

•  Course  DescripXon:    –  IntroducXon  to  computer  networks  and  protocols.  Study   of   the   ISO   open   systems   interconnecXon  model,   with   emphasis   on   the   physical,   data   link,  network,   and   transport   layers.  Discussion  of   IEEE  802,  OSI,  and  Internet  protocols.    

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Course  Outline  (4)  

•  Prerequisites:  – ECE  175,  SIE  305,  All  students  must  have  access  to  email  and  the  capability  to  access  the  class  website.  

•  Text  Book:      – Computer  Networks,    Larry  L.  Peterson  and  Bruce  S.  Davie,  Morgan  Kaufmann,  EdiXon  5,  2012.  

Course  Outline  (5)  

Grading  Policy:  –  ECE  478  Grading:    

•  Homework      15%  •  Lab          10%  •  Midterm        25%  •  Project        20%  •  Final          25%  •  Class  ParXcipaXon    5%  

 

–  ECE  578  Grading:  •  Homework      10%  •  Lab          10%  •  Midterm        20%  •  Project        20%  •  Semester  Paper    15%  •  Final  Exam      20%  •  Class  ParXcipaXon    5%  

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Course  Outline  (6)  •  Topics:  

–  IntroducXon  and  Overview    –  Data  CommunicaXons  –  Signal  Encoding  Techniques    

–  Data  Link  Control  Protocols  –  Local  Area  Network  Overview  

–  Ethernet  and  MulXple  Access  Networks  (802.3)  

–  Wireless  Networks  –  Switching  and  Bridging  

–  Basic  Internetworking  (IP)  –  Queuing  Theory  –  RouXng  Protocols  –  MulXcast  –  RouXng  among  mobile  devices  

–  TCP,  UDP  and  RPC  Protocols  

–  CongesXon  Control  and  Resource  AllocaXon    

–  Network  Security    –  ApplicaXon  Protocols    

Course  Outline  (7)  

•  Important  Deadlines:  – Midterm:  Thursday  Feb  28th  

–  Project:  •  Abstract:  February  19th  •  Outline:  March  7th  •  Full  Project  Report:  April  30th  

–  For  ECE578  Paper:  •  Abstract:  February  19th  •  Outline:  March  7th  •  Full  Paper:  April  30th  

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What  is  a  computer(data)  network?  

•  “A  Computer  network,  or  simply  a  network,  is  a  collecXon  of  computers  and  other  hardware  interconnected   by   communicaXon   channels  that   allow   sharing   of   resources   and  informaXon.”  –Wikipedia  

What  we  will  learn  in  this  course?  

•  Network  concepts:  – OSI  and  TCP/IP  models  and  layers  – Protocols  – Resources  naming  and  allocaXon  – Overcome  some  of  the  network  issues  

•  Network  Programming  – Socket  programming    

•  Designing  and  ImplemenXng  protocols  

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What  is  needed  in  order  for  two  enXXes  to  communicate?  

IdenXficaXon    

RepresentaXon    

Protocol    

Medium  

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What  disXnguishes  computer  networks  from  other  types  of  network?  

Generality,  i.e.,  carrying  many  different  types  of  

data  and  supporXng  many  applicaXons  

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ApplicaXon  

•  HTTP  Example:  –  Request:  

•  URL:    –  hkp://www.google.com  

•  Message:    –  GET  /  HTTP/1.1  

–  Response  Message:  HTTP/1.1  200  OK  Date:  Thu,  10  Jan  2013  04:57:12  GMT  Expires:  -­‐1  Cache-­‐Control:  private,  max-­‐age=0  Content-­‐Type:  text/html;  charset=ISO-­‐8859-­‐1  Set-­‐Cookie:  PREF=ID=9420873b740bdae0:FF=0:TM=1357793832:LM=1357793832:S=3lX5Dygwj7TUEJNG;  expires=Sat,  10-­‐Jan-­‐2015  04:57:12  GMT;  path=/;  domain=.google.com,  NID=67=gcb50ZfG7QxkGuenxYWASedkuFHG3nWV1Nn7-­‐XyEj-­‐oXdvXTQkgISxUpkTpqYJX4Nt12dnY-­‐BWSTd2solDDhJD-­‐vxqHCWCy6zpRkG5z6kZjlL7rzmphtF-­‐VCKN92VaE;  expires=Fri,  12-­‐Jul-­‐2013  04:57:12  GMT;  path=/;  domain=.google.com;  HkpOnly  P3P:  CP="This  is  not  a  P3P  policy!  See  hkp://www.google.com/support/accounts/bin/answer.py?hl=en&answer=151657  for  more  info.”  Server:  gws  X-­‐XSS-­‐ProtecXon:  1;  mode=block  X-­‐Frame-­‐OpXons:  SAMEORIGIN  ConnecXon:  close  

HTML  Document  

*  This  slide  is  from  the  original  slides  supplied  with  the  text-­‐book  

Requirements

•  Application Programmer –  List the services that his application needs: delay

bounded delivery of data •  Network Designer

–  Design a cost-effective network with sharable resources

•  Network Provider –  List the characteristics of a system that is easy to

manage

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*  This  slide  is  from  the  original  slides  supplied  with  the  text-­‐book  

Connectivity •  Need to understand the

following terminologies –  Scale –  Link –  Nodes –  Point-to-point –  Multiple access –  Switched Network

•  Circuit Switched •  Packet Switched

–  Packet, message –  Store-and-forward

(a)  Point-to-point (b)  Multiple access

*  This  slide  is  from  the  original  slides  supplied  with  the  text-­‐book  

Connectivity •  Terminologies (contd.)

–  Cloud –  Hosts –  Switches –  internetwork –  Router/gateway –  Host-to-host connectivity –  Address –  Routing –  Unicast/broadcast/

multicast

(a)  A switched network (b)  Interconnection of networks

(a)

(b)

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*  This  slide  is  from  the  original  slides  supplied  with  the  text-­‐book  

Cost-Effective Resource Sharing

•  Resource: links and nodes

•  How to share a link? –  Multiplexing –  De-multiplexing –  Synchronous Time-division

Multiplexing •  Time slots/data

transmitted in predetermined slots

MulXplexing  mulXple  logical  flows  over  a  single  physical  link  

*  This  slide  is  from  the  original  slides  supplied  with  the  text-­‐book  

Cost-Effective Resource Sharing

•  FDM: Frequency Division Multiplexing

•  Statistical Multiplexing –  Data is transmitted based

on demand of each flow. –  What is a flow? –  Packets vs. Messages –  FIFO, Round-Robin,

Priorities (Quality-of-Service (QoS))

–  Congested? •  LAN, MAN, WAN •  SAN (System Area

Networks

A  switch  mulXplexing  packets  from  mulXple  sources  onto  one  shared  link  

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*  This  slide  is  from  the  original  slides  supplied  with  the  text-­‐book  

•  Logical Channels –  Application-to-Application communication path or a

pipe

Support for Common Services

Process  communicaXng  over  an  abstract  channel  

*  This  slide  is  from  the  original  slides  supplied  with  the  text-­‐book  

Common Communication Patterns

•  Client/Server •  Two types of communication channel

–  Request/Reply Channels –  Message Stream Channels

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*  This  slide  is  from  the  original  slides  supplied  with  the  text-­‐book  

Reliability •  Network should hide the errors •  Bits are lost

–  Bit errors (1 to a 0, and vice versa) –  Burst errors – several consecutive errors

•  Packets are lost (Congestion) •  Links and Node failures •  Messages are delayed •  Messages are delivered out-of-order •  Third parties eavesdrop

*  This  slide  is  from  the  original  slides  supplied  with  the  text-­‐book  

Network Architecture

Example of a layered network system

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*  This  slide  is  from  the  original  slides  supplied  with  the  text-­‐book  

Network Architecture

Layered  system  with  alternaXve  abstracXons  available  at  a  given  layer