Wireless network management

Computer Networks Laboratory TECHNION - Israel

Department of Electrical Engineering institute of technology

Wireless network management (web application Students : Tzafrir Sharon Tzour

Supervisor : Nadav Lavi Table of contents

Project goal 3

Wireless LAN . 4

802 .11 protocol 4

AVAYA a ccess point . 5

The access point properties . 5

SNMP protocol . 6

Microsoft .NET developing tool . 7

SQL - structured query language . 7

Create a simple web application . 9

Wireless LAN management web application . 21

Database structure . 21

Application

br structure . 22

Accessing the access point 26

Appendixes . 27

Application code . 27

webform1 . 27

webform3 . 28

webform2 . 31

avaya .cs . 49

snmp .cs . 50

1 . Project goal

The wireless network is highly dynamic , the number of users in each access point is changing all the time and therefore those kinds of networks requires a powerful management tool that gives the network manager the capability to control the network in real time from anywhere

The project goal was to crate a web application (using Microsoft .NET environment ) that will provide easy access for network management to the network manager

The application includes 3 modules

Main application - this module includes the network manager interface such as the login window , user management functions and Access Point management functions

Database interface - this module deals with the access to the database using SQL

Access point configuration - this module deals with the access to the Access Points in to get or set the Access Point properties using the SNMP protocol

Later on , a detailed explanation on each of these modules will be given

2 . Wireless LAN

2 .1 . 802 .11 protocol

The 802 .11 protocol is defined for a wireless LAN (Local Area Network and is based on a cellular architecture in which the network is divided into cells where each cell (called a Basic Service Cell (BSS ) is controlled by a base station called an Access Point (AP

The basic access mechanism implemented in the protocol is a Carrier Sence Multiple Access with Collision Avoidance (CSMA /CA . The CSMA protocol works as follows : if a station wishes to transmit information through it network , it senses the medium . In case the medium is busy (another station in the network is currently transmitting information then the station will delay its transmission requests to a later time Otherwise , the medium is free and the station is allowed to transmit the desired information

The problem with the CSMA protocol is the case where a collision occurs A collision may occur if two different stations sense the medium as free and begin to transmit information . For this purpose , we use a collision avoidance mechanism : a station willing to transmit senses the medium . If the medium is busy , it defers its request . Otherwise , it sends an RTS (Request To Transmit ) which includes the source , destination and the duration of the transaction . If the medium is free then the destination station will respond with a packet called CTS (Clear To Send ) which will include the same duration information and once the source station receives this...