Understanding the network.pdf - Back to Home

o Bandwidth utilization rates
o Ratio between broadcast and "real" network traffic
o Protocol utilization and percentage rates
o Percentage of packet loss and packet retransmission
o Average transmission rate
Network performance validation begins when the network is first deployed. During
the initial deployment network, utilization data should be collected. This data is used
first to assess if the original design assumptions for network utilization were correct,
or they were over or under expectations. After the first round of performance
validation, and depending on the outcome, adjustments might need to be made. It
is important to realize that no matter how much testing and modeling is done before
a deployment, real user traffic is the only real test of network performance. If the
network capacity is inadequate, additional resources or a topology change might be
needed. If the network has excess capacity, cost savings might be gained by scaling
back under-utilized WAN and remote access capability. After these adjustments are
made, a second round of validation testing should begin. If no further adjustments
are needed, this data could determine the network's average utilization and peak
utilization rate. These values can then be used as the network's performance
baseline. Future performance sampling can be compared against this baseline to
determine if configuration changes are needed or if additional resource re-allocation
is required.
The initial baseline can also be the basis for performance SLAs and for evaluating
performance affecting network problems. Long-term monitoring of essential
network access points such as network backbone interfaces gateway interfaces,
remote access servers, and file and database servers is also quite desirable. Often,
shifts in network usage can be easily identified by examining histograms of
important network resources.
The area of performance management has always been a concern for network
administrators of large shared transmission medium and WAN networks. With the
arrival and mass deployment of network switches and high bandwidth WAN links,
the importance of performance management has been reduced somewhat. It's not
that monitoring is no longer needed, but that network switches make the collection
of network segment performance data samples very difficult. The growing
importance of network-intensive applications will drive new approaches to network
sampling, however, because these new applications make performance
management even more vital.
SNMP
SNMP is the de facto protocol for network management. It is part of the TCP/IP
Internet protocol suite. Its predecessors are the Simple Monitoring Gateway