Transcript Network Technologies (TCP/IP Suite)

Network Technologies
(TCP/IP Suite)
Tahir Azim
[email protected]
Agenda
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Logistics
Introduction
Logistics
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Lectures: Thu 9:00 - 9:50 am, Fri 2:20-4:10 pm
Course home page:
 http://www.niit.edu.pk/~tahir/tcpip
Class Yahoo! group and mailing list:
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[email protected]
Office hours:
 Tahir: Thursday 2:00 pm – 4:00 pm
References:
 Course based on last year’s 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
Assignments
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Hopefully, the most interesting part of the whole course
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Written Assignments (5%)
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3-4 Problem Sets
To reinforce understanding of TCP and IP concepts
Mostly mathematical but also include trying out network tools and utilities
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e.g. Ethereal, traceroute, MonALISA
Programming Assignments (15%)
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C/C++ Sockets
Projects based on the Stanford Virtual Network System (VNS)
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Simplified IP router implementation
Simple TCP implementation
Hard! There will be extra hints and code snippets to simplify it for you
Quizzes and Exams
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Quizzes (10%)
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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%)
Plagiarism Policy
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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.
Books
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Required: Computer Networks: A Systems
Approach, Peterson & Davie, 3rd edition.
Optional:
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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
Course Schedule
Duration
Topic
Logistics and Course Introduction
(0.5 weeks)
Basic Concepts
(2 weeks)
Definitions
Layered Architectures and the OSI stack
Queuing & Routing
Internet Protocol (IP)
(1 weeks)
IP Addressing
Fragmentation & Reassembly
Subnetting and CIDR
(1 week)
Packet Forwarding
(1 week)
Routing Algorithms
(2 weeks)
Distance Vector Routing (Bellman-Ford)
Link State Routing (OSPF)
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)
Course Schedule
(continued…)
Duration
Topic
Transport Layer Protocols and Reliable Data Transmission
(2 weeks)
TCP
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)
Let’s start!
But first… any questions?
The Mail Service
Stanford
Nick
Admin
MIT
Dave
Admin
Characteristics of the mail
system
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Each envelope is individually routed.
No time guarantee for delivery.
No guarantee of delivery in sequence.
No guarantee of delivery at all!
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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?
An Introduction to the mail
system
Stanford
MIT
Application Layer
Nick
Dave
Transport Layer
Admin
Admin
Network Layer
Link Layer
An Introduction to the Internet
Leland.Stanford.edu
Athena.MIT.edu
Application Layer
Nick
Dave
Transport Layer
O.S.
Datagram
Data
Header
Data
Header
Network Layer
Link Layer
O.S.
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!
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Things get lost
Acknowledgements
Retransmission
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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?
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
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Transport Layer
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Network Layer
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Provides reliable, in-sequence delivery of data
from end-to-end on behalf of application.
Provides “best-effort”, but unreliable, delivery of
datagrams.
Link Layer
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Carries data over (usually) point-to-point links
between hosts and routers; or between routers
and routers.
An Introduction to the mail
system
Stanford
MIT
Application Layer
Nick
Dave
Transport Layer
Admin
Admin
Network Layer
Link Layer
Some questions about the mail system
How many sorting offices are needed and
where should they be located?
 How much sorting capacity is needed?
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How can we guarantee timely delivery?
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Should we allocate for Mother’s Day?
What prevents delay guarantees?
Or delay variation guarantees?
How do we protect against fraudulent mail
deliverers, or fraudulent senders?