Network Management Functions -

Performance

Network Management

1

2

Week Topic

Week 1 Computer Networks - Network Management Architectures & Applications

Week 2 Network Management Standards Architectures & Applications

Week 3 Simple Network Management Protocol - SNMP v1, ASN, MIB, BER

Week 4 Network Management Functions - Fault

Week 5 Simple Network Management Protocol - SNMP v2 - Configuration

Week 6 Network Management Functions - Accounting

Week 7 Midterm

Week 8 Simple Network Management Protocol - SNMP v3 - Performance

Week 9 Network Management Functions – Security

Week 10 Remote Network Monitoring RMON 1, SLA

Week 11 Remote Network Monitoring RMON 2

Week 12 Management Tools, Systems and Applications

Week 13 NM Project Presentations

Week 14 NM Project Presentations

Week 15 NM Project Presentations

Lectures Schedule

OSI NM Architecture and Model

3

Netw

ork

Manag

em

ent

Manager

Agent

Object

Structure of Management Information (SMI)

Management Information Base (MIB)

Protocol Data Unit (PDU)

Organization Model

Information Model

Communication Model

Functional Model

Configuration Management (CM)

Fault Management (FM)

Performance Management (PM)

Security Management (SM)a

Accounting Management (AM)

Traffic monitoring

Throughput

Utilisation

Corporate

Network

Management

Admini-

stration

Mgmt

Capacity

Mgmt Provisioning

Mgmt

Accounting

Mgmt

Perfor-

mance

Mgmt

Configura-

tion

Mgmt

Fault

Mgmt Security

Mgmt

Network Management Functions

4

SNMP Milestone

5

SGMP SNMP SNMP

Security SMP SNMPv2 (parties)

SNMPv2 (community) SNMPv3

draft full standard

proposed standard

implementation experience

draft standard

proposed standard

draft standard

Standard

• SMI (Structure of Management Information) Define how management information may look like – SMIv1: RFC 1155 – SMIv2: RFC2578 (currently used)

• MIBs (Management Information Bases) Tell what management information exists – MIB-I: RFC1156 – MIB-II: RFC1213

• SNMP (Simple Network Management Protocol) Define how information is exchanged – SNMPv1: RFC1157 – SNMPv2: RFC1901, 1905, 1906 – SNMPv3: RFC2571-2575

6

Structure

7

8

Performance Management

• Issues of concern to the network manager include: – What is the level of capacity utilization?

– Is there excessive traffic?

– Has throughput been reduced to unacceptable levels?

– Are there bottlenecks?

– Is response time increasing?

• Network managers need performance statistics to help them plan, manage, and maintain large networks

9

Performance Monitoring

• After availability, the second most important characteristic of a network is performance

• Performance data must be available in sufficient detail to be able to assess the bottleneck that is causing the problem and to plan appropriate remedial action

10

Performance Management: Definition

The Utilization of

• Network Resources

with

The Ability to meet

• User Service Level Objectives

11

Performance Management: Activities

• Information Gathering

– Current System (Traffic / Resources)

– System History (Logs)

• Performance Evaluation (Analysis)

For Different States / Conditions

• Understanding / Reporting

12

Network: Performance

Traffic

Process Arrival

(Rate)

Service

(Time)

Load

Busy Period

Measures

Errors Channel

Quality

Utilization Load /

Capacity

Delay

Throughput

Monitor

Traffic

Measures

Load

Limits

13

It's Not The Volume, It's The Time It Takes To Double...

• “It’s not the heat, it’s the humidity…”

• Example: Daily Usenet News volume (e.g., ~200GB/day now, doubling every 6 mos.)

Performance Management Sub-Categories and Related Activities

Collecting Baseline

Utilization Data

· Measuring link utilization using a probe

· Counting packets received/transmitted by a specific device

· Measuring device processor usage

· Monitoring device queue lengths · Monitoring device memory utilization

· Measuring total response times

Collecting a History of

Utilization Data

· Measuring utilization and response times at different times of the day

· Measuring utilization and response times on different days over an extended period

Capacity Planning

· Manually graphing or using a network management tool to graph utilization as a function of time to detect trends

· Preparing trend reports to document projected need for and the cost of network expansion.

Performance Management Sub-Categories and Related Activities (cont.)

Setting Notification

Thresholds

· Having a network management tool poll devices for values of critical parameters and graphing these values as a function of time

· Setting polling intervals · Setting alarms/alerts on those parameters when the threshold is reached or a percentage of it is reached

· Initiating an action when the threshold is reached such a sending a message to the network manager.

Building Databases

· Having the network management tool create a database of records containing device name, parameter, threshold and time for off-line analysis. · Using the database to extract time dependence of utilization

· Using the time dependence of parameters to decide when network upgrades will be necessary to maintain performance

Running Network

Simulations

· Using a simulation tool to develop a model of the network

· Using the model’s parameters and utilization data to optimize network performance

Latency

· Query/Response time interval

MRTG • Multi Router Traffic Grouper (Oeticker and Rand) • www.ee.ethz.ch/stats/mrtg/ • Generates graphic presentation of traffic on Web

• Daily view • Weekly view • Monthly view • Yearly view

Chapter 12

Example of Performance Management

18

Obtaining Baseline Measurements

• Baseline: report of network’s current state of operation

– Baseline measurements allow comparison of future performance increases or decreases caused by network changes with past network performance

• The more data gathered while establishing the baseline, the more accurate predictions will be

• Several software applications can perform baselining

19

Performance and Fault Management

• Performance management: monitoring how well links and devices are keeping up with demands

• Fault management: detection and signaling of device, link, or component faults

• Organizations often use enterprise-wide network management software – At least one network management console collects

data from multiple networked devices at regular intervals • Polling

20

Performance and Fault Management (continued)

• Each managed device runs a network management agent

– Collects information about device’s operation and provides it to network management application

• Definition of managed devices and data collected in a Management Information Base (MIB)

• Simple Network Management Protocol (SNMP): TCP/IP protocol used by agents to communicate

21

Performance and Fault Management (continued)

22

Performance and Fault Management (continued)

• Network management application can present an administrator with several ways to view and analyze data

• Network management applications are challenging to configure and fine-tune

• Multi Router Traffic Grapher (MRTG): command-line utility that uses SNMP to poll devices, collects data in a log file, and generates HTML-based views of data

23

Performance and Fault Management (continued)

Network Statistics

• Baseline

• Trouble shooting

• Capacity planning for the future

• Reports

Traffic Load:

Source HostTopN

0 100 200 300 400

Host 10

Host 9

Host 8

Host 7

Host 6

Host 5

Host 4

Host 3

Host 2

Host 1

Giga Octets

Figure 8.5 HostTop-10 Output Octets

Traffic Load: Source/Destination

Protocol Distribution

Traffic Load: Source

Figure 12.16 Load Statistics: Monitoring of Sources

Chapter 12

Traffic Load: Destination

Chapter 12

Traffic Load: Conversation

Chapter 12

Protocol Distribution

Figure 12.19 Protocol Distribution (NetMetrix)

Chapter 12

Conclusions

•SLA •Measure Performance •Meet requirements •Evaluations of the Behaviour & Cost-Effectiveness of Network Resources