Wireless Network Management Mohammad Rasol Saidat.

Wireless Network Management

Mohammad Rasol Saidat

Agenda

Network Management and its architecture

SNMP Protocol

System Architecture

Fault management system

Performance Manager

MIBs

Tools can be used in Wireless managements

Network Management

Network management is a service that employs a variety of tools, applications, and devices to assist human network managers in monitoring and maintaining networks.

Configuration Management Performance Management Fault Management Accounting Management Security Management

Network Management Architecture

Network ManagementConfiguration Management Monitors the Network and system configuration

information Each network device has a variety of version information

associated with it TCP/IP software Version 2.0

SNMP software Version 3.1

Performance Management Measures various aspects and make them available so

that the inter network performance can be maintained.

Network Management

Fault Management Detects network problems log them and automatically fix

them to keep the network running safely.

Accounting Management Measures Network Utilization parameters.

Security Management Controls unauthorized access to the network resources so

that the network is not sabotaged.

The Network Management Should meet the following :

The management interface must be...

The management mechanism must be...

•Standardized

•Extendible

•Portable

•Inexpensive

•Implemented as software only

• SNMP is a tool (protocol) that allows for remote and local management of items on the network including Servers, Workstations, Routers, Switches, Mobile stations, Base stations and other managed devices.

• Comprised of agents and managers•Agent - process running on each managed node collecting information about the device it is running on.

•Manager - process running on a management workstation that requests information about devices on the network.

What is the SNMP ?

Advantages of using SNMP

• Standardized• universally supported• extendible• portable• allows distributed management access• lightweight protocol

Ports & UDP

•SNMP uses User Datagram Protocol (UDP) as the transport mechanism for SNMP messages

•UDP Port 161 - SNMP Messages

•UDP Port 162 - SNMP Trap Messages

•Like FTP, SNMP uses two well-known ports to operate:

Ethernet Frame IP

PacketUDP

Datagram

SNMP Message CRC

SNMP network management is based on three parts:

The Three Parts of SNMP

•Rules specifying the format used to define objects managed on the network that the SNMP protocol accesses

•A map of the hierarchical order of all managed objects and how they are accessed

•Defines format of messages exchanged by management systems and agents.•Specifies the Get, GetNext, Set, and Trap operations

Nodes Types

Items in an SNMP Network are called nodes. There are different types of nodes.

Typically runs an agent process that services requests from a management node

Typically a workstation running some network management & monitoring software

A node may not support SNMP, but may be manageable by SNMP through a proxy agent running on another machine

Nodes can be both managed nodes and a management node at the same time (typically this is the case, since you want to be able to manage the workstation that your management application is running on.)

Four Basic Operations

•Get

•GetNext

•Set

•Trap

Retrieves the value of a MIB variable stored on the agent machine

(integer, string, or address of another MIB variable)

Retrieves the next value of the next lexical MIB variable

Changes the value of a MIB variable

An unsolicited notification sent by an agent to a management application (typically a notification of something unexpected, like an error)

Wireless Network

A wireless network is a computer network in which communication between machines occurs over a wireless link. Cellular networks

Orange Jordan, Zain and Umniah. Satellite networks

Iridium, NileSAT, etc. Battlefield networks

Communication between Defense departs., soldiers, etc. Wireless Local Area Networks (LAN)

IEEE 802.11

IEEE 802.11 Overview

Adopted in 1997.

The Connectionless IEEE 802.11 local networks define 2 topologies

Infrastructure Network – connected through AP’s Ad-Hoc Network – peer-to-peer communication

Overview, 802.11 ArchitectureInfrastructure Network

Overview, 802.11 ArchitectureAd-Hoc Network

Steps

1. Discovery of New Access Point

2. Transfer of PIN

3. Registration Protocol runs as EAP (Authentication) method

4. New AP Settings sent

Access PointAccess Point

RegistrarRegistrar

Transfer of PINTransfer of PINRegistration Registration

ProtocolProtocol New AP New AP SettingsSettings

DiscoveryDiscovery

Securely Securely ConnectedConnected

Setting Up a New Wireless Network

Setting Up a New Member Device

EnrolleeEnrollee

Access PointAccess Point

RegistrarRegistrar

UPnPUPnPDiscoveryDiscoveryUPnP UPnP

EventEventStart Start

(Authentic(Authentication) EAPation) EAP

New New Enrollee Enrollee

NotificationNotification

Reads PIN from Reads PIN from EnrolleeEnrollee

Registration Registration Protocol ContinuesProtocol Continues

Securely ConnectedSecurely Connected

Signal Monitoring System for managing the wireless Network

To Manage the wireless networks system a signal monitoring system can be used.

This system does not interfere with the regular network operations. Listens Measures Sends alarms

System Architecture

NETWORK MANAGEMENT CENTER

PERFORMANCE MANAGER

Cellular Network

Scanning Receivers

Implementation of the Management System

There 2 high level versions of implementation

Centralized Performance Manager

Distributed Performance Manager

FAULT MANAGEMENT SYSYTEM

THE PERFORMANCE MANAGER

THE NETWORK MANAGEMENT CENTER

The Performance Manager

The Scanner Interface

The Measurement Database

The Alarms Generator

The NMC Interface

Performance Manager Structure

MEASUREMENT DATABASE

ALARM GENERATOR

SCANNER INTERFACE

NMC INTERFACE

The Performance Manager

The Scanner Interface Two Modes

Transmit Mode – Downloads list of scanning channel identifiers and sends them to the associated scanner for measurements.

Receive Mode – collects the measured data from the scanners according to the list of channel identifiers previously sent for measurement.

The Performance Manager

The Measurement Database

It is a Relational Database that stores the received data in the scanner interface (receive mode)

It consists of tables

The Performance Manager

The Alarm Generator

If correlated results indicate poor coverage, the alarm generator generates an alarm to NMC and sends via NMC interface in performance manager structure.

The Performance Manager

The Alarm Generator Alarm contains the following information

BSC identifier BST identifier Faulty channel identifier Alarm code Alarm description Scanner identifier Scanner location Timestamp Alarm severity

The Performance Manager

The NMC Interface It enables communication between the

performance manager and the Network Management center

It has two modes Transmit – sends alarm from alarm generator to

NMC Receive – It receives the channel identifiers for

each base station and forwards the list via scanner interface

The Network Management Center

The Performance Manager Interface

The Management Information Base

The Graphical User Interface

The Network Management Center

The Performance Manager Interface Two modes

Transmit mode- Transmits the list of channels that are allocated for each BTS to NMC interface in Performance Manager

Receive mode – Receives alarm from the performance manager and stores them into MIB

The Network Management Center

The Management Information Base(MIB) The Management Information Base is a Relational

Database which stores all the information. Each area has an Operator and a team of

technicians. Each region consists of many areas and each

region is managed by supervisor and all supervisors report one super user

The MIB Structure

SUPER USER

SUPERVISOR1 SUPERVISOR2 SUPERVISOR3

Operater2Operater1 Operater2 Operater1 Operater2Operater1

The MIB Organization

The Network Management Center

The Graphical User Interface NMC includes a Graphical User Interface

containing a Geographic map of the network coverage area, with an overlay graphical presentation of the managed network elements and their Interconnections

Some advanced GUI interfaces in network management systems have the following features

Changing the color of the network element based on severity of the alarm

Blinking occurs when the network element has some emergency

Clicking on the network element gives the real time information about the element configuration and pending alarms

The Graphical User Interface

The Graphical user interface

Examples of ManagmentTools

• Protocol Analyzer• WhatsUp• MRTG• MRTG-UFFE• NMS

Packet AnalyzerDevice that lets you see packets on the wireOur tool is a Network Associates’ SnifferPrimarily a troubleshooting toolHowever, by capturing the data on a connection (e.g. uplink) over time you can collect key network statistics Flaw: It only does ONE connection at a timeProtocol Analyzer measures packets

Whats up

• Monitors network devices (e.g. switches & routers) servers & server applications

• uses ICMP (ping) and TCP/IP ports• If device responds server is deemed to be up• Flaw: Just because the web server port opens

on port 80 this does not necessarily mean the web server is working properly; it just means that the web server is up

• WhatsUp measures availability• Uses drill down method (example to follow)

Whats up

MRTG

• MRTG = Multi Router Traffic Grapher• Monitors bits in and out of a network device (eg. Switch port, router

port, NIC card)• Using SNMP it queries the switch for port activity once every five

minutes• Keeps daily, weekly monthly and yearly statistics on that port• Flaw 1: If there is a lot of usage then the device(s) attached to the

port are running well. If usage is low then ????• Flaw 2: It monitors amount of bits not the number of packets. If you

had a Denial of Service attack with a large number of small packets MRTG would not indicate a problem

• MRTG measures bandwidth• Like WhatsUp, MRTG uses drill down method

MRTG UFFE

• MRTG-UFFE = MRTG’s User Friendly Front End

• Add on to MRTG• Homegrown utility that

documents the important (special, unusual, busy) connections on campus

• Hyperlinks to MRTG• MRTG-UFFE measures

connections

Conclusion

The signal Monitoring system improves the reliability and the quality of service of a wireless network by efficient failure detection and location.

It also improves the Overall network coverage and availability of network resources.

References

Jelena Vucetic, paul Kline: “signal Monitoring system”, IEEE Dynamic Telecommunications 1998

S. M. Dauber: “Finding Fault”, BYTE Magazine, McGraw-Hill, Inc. New York, NY, March 1991

0. Wolfson, S. Sengupta, Y. Yemini: “Managing Communication

Networks by Monitoring Databases”, IEEE Transactions on Software

Engineering m Vol. 17, No. 9, September 1991 L. Feldkhun: “Integrated Network Management Systems”, Proceedings

First International Symposium on Integrated Network Management, 1989

http://www.powershow.com/view/1cfe58-M2YzO/Wireless_Network_Management_SANDEEP_powerpoint_ppt_presentation

Questions

What are the Advantages of the Fault Management system?

Ans: improves the reliability and the quality of service of a wireless network.

What are the system design Considerations to be considered to while designing the Monitoring management system?

Ans: No. of Scanners and the locations where they should be placed. For the cost to be minimum the no. of scanners should be less.

How does this fault management system improve reliability and Network coverage?

Ans: Efficient failure detection and also the location of the failure.