New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 1
CSCI-370/EENG-480
Computer Networks
Khurram Kazi
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 2
Major sources of the slides for this lecture
Slides from Tanenbaum’s and William Stallings’ website are used in this lecture
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 3
Course Outline
This course provides an introduction to the fundamentals and the applications of data communications networks. Network architectures, topology, protocols, network services and models will be discussed. Some of the protocols the course will cover are: Synchronous Optical Networks (SONET) (Wide Area Network) Optical Transport Hierarchy (OTH) (Wide Area Network) Ethernet (10/100, Gigabit Ethernet) (LAN, Metro and Wide Area Networks) MultiProtocol Label Switching (MPLS) (Layer 2.5) Protocols based on Internet Protocol (IP) (Layer 3 and above) Switching and routing architectures will be presented (Hardware/Software
implementation architectures) Time permitting we will cover some aspects of Cellular Networking and Next
Generation Network Architecture (NGN) Services provided by various networks Network Security OPNET (a premier network simulator) will be used in simulating various
aspects of networking concepts.
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 4
Grading Policy
Assignments, short quizzes and presentations on assigned papers (during the course of the semester) 30%
1 Midterm Test 30% Final Project 40% Final Projects will be in any topic of interest within the Data
Networking field There will be an Oral presentation of the project along with a
written report NYIT’s Academic Integrity policy will be strictly
enforced. Any student found to be cheating (in the assignments, quizzes, Midterm etc.) will get a straight “F”
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 5
Do’s and Don’ts for the Final Project
DO NOT use any report / design from the net. I will know if you did!!
Properly referenced work that is not plagiarized is acceptable Most of it should be your work!! Select the topic that interests you. Be creative in it! Designing
some aspect in software or hardware will be highly encouraged as opposed to doing an overview/report on some networking technology
By mid semester have a good idea of your project Team of 2 students working on the same project is allowed.
Each team member’s task within the project should be explicitly defined.
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 6
Intended Results at the Culmination of the Course You should have a good understanding of networking
technologies Should be able to architecturally design various
components of the diverse networks Design of a router/switching Network Element
Line CardsSwitch FabricsProtocol Handling
Ability to figure out which aspect is implemented in hardware and what is designed in the software
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 7
Books
Required Textbooks: Computer Networks, Andrew S. Tanenbaum, 4th Edition,
Prentice Hall, 2003, ISBN 0-13-066102-3 Recommended Textbooks:
1) The Internet and Its Protocols; A Comparative Approach, Adrian Farrel, Morgan Kaufmann Publishers, 2004, ISBN 1-55860-913-X
2) Internetworking with TCP/IP Principles, Protocols, and Architectures, Douglas Comer, 4th Edition, Volume 1, Prentice Hall, 2000, ISBN 0-13-018380-6
3) Optical Networking Standards: A Comprehensive Guide for Professionals, edited by Khurram Kazi, Springer, 2006, ISBN 0-387-24062-4
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 8
Useful websites
Tanenbaum’s website at Prentice Hall http://authors.phptr.com/tanenbaumcn4/
William Stalling’s (Another good text book on data and computer networks) Website http://www.williamstallings.com/DCC/DCC8e.html
Standards Organizations and Industry Forums Internet Engineering Task Force
http://www.ietf.org/ MetroEthernet Forum
http://metroethernetforum.org/page_loader.php?p_id=84&index=1 International Telecommunication Union (ITU): The leading United Nations agency for
information and communication technologies http://www.itu.int/net/home/index.aspx
IEEE (Institute of Electrical and Electronics Engineers) LAN/MAN Standards Committee http://www.ieee802.org/
OPNET (Network simulator that we will be using) www.opnet.com
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 9
ITU
Main sectors• Radiocommunications
• Telecommunications Standardization
• Development
Classes of Members• National governments
• Sector members
• Associate members
• Regulatory agencies
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 10
IETF
The Internet Engineering Task Force (IETF) is a large open international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet. It is open to any interested individual. The IETF Mission Statement is documented in RFC 3935.
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 11
IEEE 802 Standards
The 802 working groups. The important ones are marked with *. The ones marked with are hibernating. The one marked with † gave up.
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 12
Implication of the Designs we work on; keep few things in mind!
During the design process we always make trade-offs Trade-offs can be based on time to market, cost
implications, complexity, environmental considerations etc. Ethics: Keep in mind the implications of what you are
designing, how it impacts the society!! Privacy vs. Security is a big issue in networking
Network designs inherently deal with Implementing of standardized solutions based on regional or
global standards developed by industry forums or international standards organizations
Power consumption considerations: Making the Designs Green; Environmental friendly!!
Cost/performance trade-offs
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 13
Uses of Computer Networks
• Business Applications
• Home Applications
• Mobile Users
• Social Issues
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 14
Business Applications of Networks
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 15
Business Applications of Networks (2) The client-server model involves requests
and replies.
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 16
Home Network Applications
Access to remote informationPerson-to-person communicationInteractive entertainmentElectronic commerce
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 17
Home Network Applications (2)
In peer-to-peer system there are no fixed clients and servers.
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 18
Home Network Applications (3)
Some forms of e-commerce.
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 19
Types of Network
Metropolitan Area NetworksLocal Area NetworksWide Area NetworksCellular NetworksWireless Networks (could be
Broadband Networks or LANs)Home NetworksInternetworks
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 20
Network classification based on distances Classification of interconnected processors
by scale.
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 21
Fuzzy Networking Demarcation Points
Metro Edge
Metro Area Network
(Metro Core)
Premise(Enterprise Networks)
Metro Edge
Metro Area Network
(Metro Core)
Wide Area Network(Core/backbone/
Long Haul)
Bigger Pipes less intelligence in transportSmaller Pipes Higher intelligence in aggregation/
switching
Premise(Enterprise Networks)
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 22
A Communications Model
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 23
Communications Tasks
Transmission system utilization Addressing
Interfacing Routing
Signal generation Recovery
Synchronization Message formatting
Exchange management Security
Error detection and correction Network management
Flow control
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 24
Data Communications Model
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 25
Transmission Medium Selection is a basic choice
internal use entirely up to business long-distance links made by carrier
Rapid technology advances change mix fiber optic Copper Cable (still alive and widely used) Wireless (microwaves, satellite, light waves, cellular
etc.) Transmission costs still high (but decreasing as time
progresses) Hence interest in efficiency improvements (never
ending so to speak!)
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 26
Some of the Drivers for Innovative Networking Technologies
Growth of number & power of computers is driving need for interconnection
also seeing rapid integration of voice, data, image & video technologiesVoice over IPIPTVTraditional net connectivity for data
transmissions
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 27
Types of Networks: Wide Area Networks
Span a large geographical area Cross public rights of way Rely in part on common carrier circuits Technologies used include:
circuit switching packet switching (IP or MPLS based) Ethernet based transport Legacy Technologies
frame relayAsynchronous Transfer Mode (ATM)
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 28
Types of Networks:Wide Area Network
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 29
Relation between hosts on LANs and the subnet.
Types of Networks:Wide Area Network
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 30
Types of Networks:Wide Area Network
A stream of packets from sender to receiver.
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 31
Circuit Switching
Uses a dedicated communications path established for duration of conversation
Comprising a sequence of physical links with a dedicated logical channel
e.g. telephone network
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 32
Packet Switching
Data sent out of sequence over diverse paths Small chunks (packets) of data at a time Packets passed from node to node between
source and destination Used for terminal to computer and computer
to computer communications
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 33
Types of Networks:Metro Area Network
MAN Middle ground between LAN and WAN Private or public network High speed Large area
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 34
Types of Networks:Metro Area Network
Headquarters to Printing site(15 miles)
HQ to Carrier Hotel(5 miles)
Printing Site to Carrier Hotel(15 miles)
2 Gigabit Ethernet Channels2 Fibre Channels1 multiplexed fiber (T1, T3, 10/100 Ethernet
1 Gigabit Ethernet Channels1 multiplexed fiber (T1, T3, 10/100 Ethernet
1 Gigabit Ethernet Channels1 multiplexed fiber (T1, T3, 10/100 Ethernet
Headquarters
Carrier Hotel
Printing site
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 35
Types of Networks:Metro Area Network
A metropolitan area network based on cable TV.
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 36
Types of Networks:Local Area Networks
Smaller scopeBuilding or small campus
Usually owned by same organization as attached devices
Data rates much higher Switched LANs, e.g. Ethernet Wireless LANs
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 37
Types of Networks:Local Area Networks
Two broadcast networks (a) Bus (b) Ring
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 38
Types of Networks:Wireless Networks
Categories of wireless networks:
System interconnectionWireless LANsWireless WANs
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 39
Types of Networks:Wireless Networks
(a) Bluetooth configuration (b) Wireless LAN
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 40
Types of Networks:Wireless Networks
(a) Individual mobile computers (b) A flying LAN
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 41
Types of Networks:Home Networking
Computers (desktop PC, PDA, shared peripherals
Entertainment (TV, DVD, VCR, camera, stereo, MP3)
Telecomm (telephone, cell phone, intercom, fax)
Appliances (microwave, fridge, clock, furnace, airco)
Telemetry (utility meter, burglar alarm, babycam).
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 42
Home Networking:Digital Living Room
Digital Living Network Alliance (DLNA) http://www.dlna.org/en/industry/about
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 43
The Internet
Internet evolved from ARPANETfirst operational packet networkapplied to tactical radio & satellite nets alsohad a need for interoperability led to standardized TCP/IP protocols
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 44
Internet Elements
SONET/OTH (MPLS based routing)
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 45
Internet Architecture
New York Institute of Technology
Engineering and Computer Sciences
Kazi Fall 2007 CSCI 370 46
Example Configuration