Wireless LAN Topology Wireless LAN Topology VisualiserVisualiser

Project Supervisor:

Dr Arkady Zaslavsky

 

Project Team Members:

Jignesh Rambhia

Robert Mark Bram

Tejas Magia

Wireless LANWireless LAN

Wireless LAN infrastructureAllow mobile users connect to networkAccess Points

- Cisco Aironet series - Apple AirPort

Protocols used: - 80211.b - Bluetooth

Overview of functionsOverview of functions

Web accessible visualisation of system mapped onto physical locations

Active polling of access pointsDynamic discovery of access points

(not implemented)Storing data to allow for tracking of changeEvent notification

Visualiser has a Data BaseVisualiser has a Data Base

Initial registration gathers static data– Geographic location, IP address, Contact details

of point administrator

Continual polling updates dynamic data– Number of users, bytes sent and received

Browse TopologyBrowse TopologyThe user browses access point topology

through mapsFrom World… click locations to zoom in

To Country..

Browse TopologyBrowse Topology

To State..

Browse TopologyBrowse Topology

To Campus.. where a mouse roll-over displays whatever information you are authorised to see.

Browse TopologyBrowse Topology

Administer AccessAdminister AccessPoints Directly Points Directly

And a click will bring you to the Access Point’s administration page (if you have username and password)

Visualisation displays any combination of data based on user authorisation level,determined by login– Administrator can alter settings,

start and stop system– Registered user can view all parts of visualisation– Public user can view the visualisation without data

Administrator sees all, public sees none!

Authorisation LevelsAuthorisation Levels

Administrative Tool – Administrative Tool – Monitoring and ManagementMonitoring and Management

Administrator monitors status of access points– Network Traffic – users and data rates– Online or offline

Direct management of access points via links to access point web servers

Maps access points to physical locations

Display Up to date DataDisplay Up to date Data

Display current data on all access points– Human readable location data– Internet Address– MAC Address– Type of hardware– Number of users– Bytes sent in time period– Bytes received in time period

User LevelsUser Levels

Allow three levels of accessAdministrator

- alter settings, start and stop systemRegistered user

- view all parts of visualisationPublic user

- view the visualisation without data

Design PrinciplesDesign Principles

Modular – Independent subsystems

Liveliness Maintenance Extensibility

– Development of tool set Totally configurable

– All settings read from configuration file XML data storage

– No commerical databases– Human readable data format

XML data structureXML data structure XML structures nest element instances within

other element instances. Each element is a record – each XML document

has one root element World is the root

– locations Location instances

– accessPoints accessPoint instances

Locations and Access PointsLocations and Access Points

Both record types have data in commonA unique IDMap they are linked to (ID of another

Location), x and y co-ordinate of their position on that map

Data that can be displayed on the web with a rollover (HTML table tag)

LocationsLocations

Locations store data about the map that is used to visualise that location

Access Point ProfilesAccess Point Profiles The network is

heterogeneous – different types of Access Point hardware may make different data available.

A common data set is defined with a master profile

Specialisation is allowed with a type specific element

Access Point RecordsAccess Point Records Some items of data will be

displayed on their visualisation. They store a title and display value

Some items of data will be polled for updates. They must contain enough access data to allow this to happen.

PollingPolling

Each Access Point is periodically polled to update certain items of data

Different Access Points make this data available in different ways– HTTP on an internal web server– Telnet– Simple Network Management Protocol (SNMP)

The system maintains a library of classes for each access method and ensures the correct one is used for each item of data

Web data preparationWeb data preparation

Periodically a subset of the Access Point data is extracted from its XML file and stored in another, formatted for easy display

VisualisationVisualisation

Servlets are run on the server side, taking HTTP requests from users and displaying the maps with data extracted by the previous subsystem

Data entryData entry

New Access Points can be added to the system through a simple GUI.

MailingMailing

A mail system is used to implement event notification

Whenever an error has occurred in the system, notification is sent

Whenever an Access Point has not responded to polling three times in a row, a notification is sent

LoggingLogging

A logging API is used that allows logged messages to be sent to a number of places at once:– A terminal– An on-screen text component– A data file– Any number of listening ‘streams’

ControlControl

Applets to control system

TechnologyTechnology

Development Environments:– JBuilder and TextPlus to build Java classes– XML Spy to build XML files

Programming API’s– Java SDK 1.2 and Servlet libraries– Java Mail API and Activation Framework– JCE encryption API– JAXB to parse XML

LimitationsLimitationsFor XML parsing we used JAXB

– JAXB parses XML DTD files and constructs a specialised set of Java classes for them

– JAXB unmarshalls - parses XML into a set of Java objects

– JAXB marshalls – writes Java objects back to XML

– JAXB is only in its first release– It can only parse DTD’s– It does not implement all parts of DTD spec

LimitationsLimitationsAccess Techniques

– No generic access method was found– HTTP or Telnet methods both receive

formatted text that must be parsed

Dynamic discovery impossible– Addhost unreliable– No identifiable pattern in MAC addresses

Future workFuture work

Administrative Tool for Security and Trouble Shooting– Detect new access points added to system

SNMP?

– Perform data analysis for network problems

A more fluid Data entry system – for Locations, Users and Access Points