2/15/2013

1

Course outline (1/4)

The OSI architecture

Network addressing fundamentals OSI and TCP/IP models and relationship

IP address format

IP address classes

Public vs Private addresses

IP subnetting

Transport layer protocols TCP and UDP basics

Understanding port numbers

Socket based communication

TCP connection establishment and termination

TCP Bulk data flow

TCP Interactive data flow

UDP

6

Course outline (2/4)

Routing protocols Why routing?

Routing in wired networks Using static routing

Dynamic routing using RIP

Distance vector vs link state routing

Routing in mobile ad-hoc networks (MANETs) Proactive routing protocols

Reactive routing protocols

Hierarchal routing protocols

Location based routing protocols

Network performance and role of routing protocols

7

2/15/2013

2

Course outline (3/4)

Data Link layer

ARP protocol

RARP protocol

Wireless Local Area Networks (WLANs) The IEEE 802.11 family of standards specification for Medium Access

Control (MAC) and the Physical (PHY) layer for WLANs Basic MAC architecture

Coordination Functions The Distributed Coordination Function

Point Coordination Function

Hybrid Coordination Function

Quality of Service parameters at MAC sub-layer

Power Management Policies

Wireless Personal Area Networks (WPANs), IEEE 802.15

Wireless Metropolitan Area Networks (WMANs), IEEE 802.16

8

Course outline (4/4)

Special topics

Research methodologies

Presentations on special topics (student may

choose from a wide range of topics Individual

basis) 12 to 1612 to 16thth December 2011December 2011

9

2/15/2013

3

Laboratory exercises

The laboratory exercises will require the use of a network simulationsoftware, OPNET, and a Cisco IOS emulator called NetSim.

Introduction to Cisco IOS

Switches: introduction, configuration, and security.

VLANs, introduction, configuration.

Router configuration, exercises for implementing static, dynamicrouting in wired networks.

Subnetting exercises using the IOS and different network architectures

Variable length subnet masks

Access lists, introduction, configuration.

Lab exercises using OPNET*.

* If we are successful in getting a license.

10

List of Laboratory Exercises

Introduction to Network Simulators

Network traffic patterns and generation parameters

Network traffic generation using Application and Profile configuration

IPv4 header fields manipulation the Traceroute application

Analysis of the State Transition Diagram of the Transmission Control Protocol using Wireshark

packet analyzer

Modelling and Analysis of an Ethernet-LAN using OPNET

Working with the operating system of Switches and Routers Spanning Tree Protocol

Wide Area Network Modelling

Wireless Local Area Networks (WLANs) Basic Service Set setup and basic configuration

WLANs Station mobility configuration and performance analysis

Routing Information Protocol (RIP) performance analysis

Routing Protocols for MANETs Reactive routing protocols AdHoc On-Demand Distance

Vector (AODV) exercise

Routing Protocols for MANETs Proactive routing protocols Destination Sequence Distance

Vector (DSDV) exercises

Process Modelling - Basics

Process Modelling Advance exercises

11

2/15/2013

4

Books/Reference material

Data and Computer Communications (William Stallings)

Computer Networking A top-down approach featuring

the Internet (James F. Kurose, Keith W. Ross)

TCP/IP Illustrated Volume -1 (Richard Stevens)

IEEE 802.11 Standard specifications

OPNET documentation available at www.opnet.com

12

Grading Policy

The following grading policy will be used

Quizzes 15%

Assignments 10%

Midterm 25%

Final 50%

13

2/15/2013

5

Some precautions

14

Lecture-1

Some of the graphics used in this lecture are courtesy of Wendell Odom15

2/15/2013

6

Layered architecture (OSI and TCP/IP)

When we communicate on networks, there is a multitude of tasks that have to be performed: for instance:

Representing the data (voice, video, text) in the required format, presentable over the networks

Creating rules of engagement with other entities

Ensuring reliable delivery to the other end

Finding the right entity on a network of millions of entities

Reaching the right entity thousands of miles away within given delay constraints

Network access heterogeneity

End to end security - data encryption

Access security authentication rules

There are separate rules in place for performing these tasks (in the form of network protocols).

These set of rules change when either the access network, the backbone network or the form of application data changes.

So do we have to change everything altogether to accommodate an update/change?

16

Consider the simple process of requesting a home-page from a web server:

1. HTTP

2. HTML, SQL scripts, PHP

3. TCP connection

4. IP address from domain name (DNS)

5. Routing from source to destination

6. Mapping IP to MAC address (ARP and then RARP at

the other end)

7. Forming MAC/Data Link frames, specific to access

network and then ripping them apart

8. Physical transmission

9. Authentication at various levels, security of

transmission, etc, etc.17

2/15/2013

7

Simplifying the mess

The idea of grouping the long list of tasks into different layers was coined for:

Simplicity

Layer to layer abstraction

Providing independence to developers at various layers (Modular engineering)

So, now we can group the tasks into independent layers:

Network application design, data representation and formatting

End to end delivery of data between peers

Addressing, finding end to end peers

Local (first hop) dealing, addressing, error detection, framing/grouping

Physical transmission

However, grouping tasks into layers without a standard was not a viable option and the result is:

Vendor interoperability issues

Conflicts in developments

18

The Open Systems Interconnections

(OSI)networking model

The International Standardization Organization (ISO)

developed the OSI model to standardize the protocol

development.

7

6

5

4

3

2

119

2/15/2013

8

OSI layers and their functions

Application Layer: serves as an interface between the rest of the protocol

stack and network applications.

Presentation Layer: defines and negotiates presentation format of data

exchanged over the network, e.g. HTML. Compression and encryption is

also defined by the OSI as a presentation layer service.

Session Layer: Its job is to facilitate in starting, controlling and ending

communication sessions over a network.

Transport Layer: provides several significant services mainly related with

end to end transport to data across a network, error recovery and flow

control.

Network Layer: defines three main features: (1) Logical addressing of

nodes in a network, routing (forwarding function) and route discovery.

Logical (Internet Protocol IP) address identifies a device in an IP based

network, route discovery function selects best routes out of multiple

available routes which is used by a forwarding function.20

OSI layers and their functions

Data link Layer: serves for controlling, monitoring the exchange of data

(frames) over a medium. Error detection, framing (dividing into right sized

chunks) and medium access regulation are some of the key functions

assigned to protocols that reside at this layer.

Physical Layer: defines the characteristics that a transmitter and receiver

should have to communicate on a physical/wireless medium. Modulation

schemes, connectors, multiplexing etc, are dealt at this layer.

21

2/15/2013

9

OSI encapsulation concepts

As we will see that TCP/IP gives a separate name to data according to the

level (layer) for instance it is called segment, packet and frame at

Transport, Network and Data link layers respectively.

OSI naming is different, rather more generic; called protocol data unit

(PDU).

A layer x PDU consists of encapsulated data, header and trailer attached

at layer x.

For instance, an MSDU received at MAC sublayer of IEEE 802.11, becomes

a MAC PDU (MPDU) after MAC headers are attached and later on

becomes a PHY PDU (PPDU) at the PHY.

22

TCP/IP Networking model a touch of

history

Like many successful projects, the roots of TCP/IP networking

model trace back to U.S. DoD project.

It was backed by a number of researchers (free lance) from a

number of universities.

Around the late 80s there were several proprietary

networking models, the OSI and TCP/IP to compete.

The slow standardization process of OSI, idealistic approaches

slowed down its success compared to the very prolific TCP/IP

model.

OSI is used a reference model, TCP/IP as a practical model.

23

2/15/2013

10

TCP/IP Networking model

Frame

Packet

Segment

The protocols in the TCP/IP suite are defined in documents called Requests

for Comments (RFCs).

By implementing a protocol x defined in a certain RFC, a network-station

can confidently communicate with a peer on a network without considering

interoperability issues.

24