Transcript Wireless LAN Topology Visualiser

Wireless LAN Topology
Visualiser
Project Supervisor:
Dr Arkady Zaslavsky
Project Team Members:
Jignesh Rambhia
Robert Mark Bram
Tejas Magia
Wireless LAN

Wireless LAN infrastructure
 Allow mobile users connect to network
 Access Points
- Cisco Aironet series
- Apple AirPort
 Protocols used:
- 80211.b
- Bluetooth
Overview of functions

Web accessible visualisation of system
mapped onto physical locations
 Active polling of access points
 Dynamic discovery of access points
(not implemented)
 Storing data to allow for tracking of change
 Event notification
Visualiser has a Data Base
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Initial registration gathers static data
– Geographic location, IP address, Contact details
of point administrator
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Continual polling updates dynamic data
– Number of users, bytes sent and received
Browse Topology
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The user browses access point topology
through maps
 From World… click locations to zoom in
Browse Topology
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To Country..
Browse Topology
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To State..
Browse Topology
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To Campus.. where a mouse roll-over
displays whatever information you are
authorised to see.
Administer Access
Points Directly
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And a click will
bring you to the
Access Point’s
administration
page (if you have
username and
password)
Authorisation Levels
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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
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Administrator sees all, public sees none!
Administrative Tool –
Monitoring and Management
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Administrator monitors status of access
points
– Network Traffic – users and data rates
– Online or offline
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Direct management of access points via
links to access point web servers
 Maps access points to physical locations
Display Up to date Data
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Display current data on all access points
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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 Levels

Allow three levels of access
 Administrator
- alter settings, start and stop system
 Registered user
- view all parts of visualisation
 Public user
- view the visualisation without data
Design Principles

Modular
– Independent subsystems
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Liveliness
Maintenance
Extensibility
– Development of tool set
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Totally configurable
– All settings read from configuration file
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XML data storage
– No commerical databases
– Human readable data format
XML data structure
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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
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Location instances
– accessPoints
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accessPoint instances
Locations and Access Points
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Both record types have data in common
 A unique ID
 Map 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)
Locations
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Locations store data about the map that is
used to visualise that location
Access Point Profiles
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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 Records
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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.
Polling
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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)
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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 preparation
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Periodically a subset of the Access Point
data is extracted from its XML file and
stored in another, formatted for easy display
Visualisation
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Servlets are run on the server side, taking
HTTP requests from users and displaying
the maps with data extracted by the
previous subsystem
Data entry
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New Access
Points can be
added to the
system through a
simple GUI.
Mailing

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
Logging

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’
Control
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Applets to
control system
Technology
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Development Environments:
– JBuilder and TextPlus to build Java classes
– XML Spy to build XML files
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Programming API’s
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Java SDK 1.2 and Servlet libraries
Java Mail API and Activation Framework
JCE encryption API
JAXB to parse XML
Limitations
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For XML parsing we used JAXB
– JAXB parses XML DTD files and constructs a
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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
Limitations
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Access Techniques
– No generic access method was found
– HTTP or Telnet methods both receive formatted
text that must be parsed
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Dynamic discovery impossible
– Addhost unreliable
– No identifiable pattern in MAC addresses
Future work
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Administrative Tool for Security and
Trouble Shooting
– Detect new access points added to system
 SNMP?
– Perform data analysis for network problems
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A more fluid Data entry system – for
Locations, Users and Access Points