Network Technologies (TCP/IP Suite)

1
Network Technologies (TCP/IP Suite)

• Tahir Azim
• tazim_at_niit.edu.pk

2
Agenda

• Logistics
• Introduction

3
Logistics

• Lectures Thu 900 - 950 am, Fri 220-410 pm
• Course home page
• http//www.niit.edu.pk/tahir/tcpip
• Class Yahoo! group and mailing list
• tcpip-niit_at_yahoogroups.com
• Office hours
• Tahir Thursday 200 pm 400 pm
• References
• Course based on last years TCP/IP course by Umar
  Kalim and CS244A Networks Course at Stanford by
  Prof Nick McKeown
• Many slides reused from Umar Kalim and Nick
  McKeown

4
Assignments

• Hopefully, the most interesting part of the whole
  course
• Written Assignments (5)
• 3-4 Problem Sets
• To reinforce understanding of TCP and IP concepts
• Mostly mathematical but also include trying out
  network tools and utilities
• e.g. Ethereal, traceroute, MonALISA
• Programming Assignments (15)
• C/C Sockets
• Projects based on the Stanford Virtual Network
  System (VNS)
• Simplified IP router implementation
• Simple TCP implementation
• Hard! There will be extra hints and code snippets
  to simplify it for you

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Quizzes and Exams

• Quizzes (10)
• Six quizzes, which will all be un-announced
• Missed quizzes cannot be retaken
• The best 4 out of the 6 quizzes will count
  towards the total
• OHTs (25)
• Finals (45)

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Plagiarism Policy

• IMPORTANT!
• Anyone found guilty of plagiarizing any material
  from another student or from the Web, without
  proper references, will have all their Quiz and
  Assignment marks cancelled.
• When references are cited, students will be asked
  to describe their work verbally.

7
Books

• Required Computer Networks A Systems Approach,
  Peterson Davie, 3rd edition.
• Optional
• Computer Networking A Top-Down Approach
  Featuring the Internet, Third Edition.
• Unix Network Programming, Volume 1 The Sockets
  Networking API (3rd Edition)
• Various papers and RFCs from time to time

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Course Schedule
Topic Duration
Logistics and Course Introduction (0.5 weeks)
Basic Concepts Definitions Layered Architectures and the OSI stack Queuing Routing (2 weeks)
Internet Protocol (IP) IP Addressing Fragmentation Reassembly (1 weeks)
Subnetting and CIDR (1 week)
Packet Forwarding (1 week)
Routing Algorithms Distance Vector Routing (Bellman-Ford) Link State Routing (OSPF) (2 weeks)
Inter-AS routing (BGP) (0.5 week)
Dynamic Host Configuration Protocol (DHCP), Network Address Translation (NAT) (1.5 weeks)
Transport Layer Protocols and User Datagram Protocol (UDP) (0.5 week)
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Course Schedule (continued)
Topic Duration
Transport Layer Protocols and Reliable Data Transmission TCP (2 weeks)
TCP Congestion Control (1 weeks)
TCP Congestion Avoidance (0.5 weeks)
Quality of Service (1 weeks)
Application Protocols (HTTP, FTP) (1.5 week)
VPNs, SNMP (1 week)
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Lets start!

• But first any questions?

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The Mail Service
MIT
Stanford
Dave
Nick
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Characteristics of the mail system

• Each envelope is individually routed.
• No time guarantee for delivery.
• No guarantee of delivery in sequence.
• No guarantee of delivery at all!
• Things get lost
• How can we acknowledge delivery?
• Retransmission
• How to determine when to retransmit? Timeout?
• Need local copies of contents of each envelope.
• How long to keep each copy.
• What if an acknowledgement is lost?

13
An Introduction to the mail system
MIT
Stanford
Application Layer
Nick
Dave
Transport Layer
14
An Introduction to the Internet
Athena.MIT.edu
Leland.Stanford.edu
Nick
Dave
Datagram
15
Characteristics of the Internet

• Each packet is individually routed.
• No time guarantee for delivery.
• No guarantee of delivery in sequence.
• No guarantee of delivery at all!
• Things get lost
• Acknowledgements
• Retransmission
• How to determine when to retransmit? Timeout?
• Need local copies of contents of each packet.
• How long to keep each copy?
• What if an acknowledgement is lost?

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Characteristics of the Internet (2)

• No guarantee of integrity of data.
• Packets can be fragmented.
• Packets may be duplicated.

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Layering in the Internet

• Transport Layer
• Provides reliable, in-sequence delivery of data
  from end-to-end on behalf of application.
• Network Layer
• Provides best-effort, but unreliable, delivery
  of datagrams.
• Link Layer
• Carries data over (usually) point-to-point links
  between hosts and routers or between routers and
  routers.

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An Introduction to the mail system
MIT
Stanford
Application Layer
Nick
Dave
Transport Layer
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Some questions about the mail system

• How many sorting offices are needed and where
  should they be located?
• How much sorting capacity is needed?
• Should we allocate for Mothers Day?
• How can we guarantee timely delivery?
• What prevents delay guarantees?
• Or delay variation guarantees?
• How do we protect against fraudulent mail
  deliverers, or fraudulent senders?