Network Management Functions -
Performance
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
NM Project Presentations
OSI NM Architecture and Model
Netw
ork
Manag
ement
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)
Traffic monitoring
Throughput
Corporate
Network
Management
Admini-
stration
Mgmt
Capacity
Mgmt
Provisioning
Mgmt
Accounting
Mgmt
Perfor-
mance
Mgmt
Configura-
tion
Mgmt
Fault
Mgmt
Security
Mgmt
SNMP Milestone
SGMP SNMP
Security SMP
SNMP
SNMPv2
(parties)
(community) SNMPv3
SNMPv2
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
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?
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
Performance Management:
Definition
The Utilization of
• Network Resources
with
The Ability to meet
Performance Management:
Activities
• Information Gathering
–
Current System (Traffic / Resources)
– System History (Logs)
• Performance Evaluation (Analysis)
It's Not The Volume, It's The Time It
Takes To Double...
• “It’s not the heat, it’s the humidity…”
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
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
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
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
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
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)
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
Network Statistics
• Baseline
• Trouble shooting
Traffic Load: Source
Traffic Load: Destination
Traffic Load: Conversation
Protocol Distribution
Figure 12.19 Protocol Distribution (NetMetrix)
