Burst analysis on a Mirror or Packet Broker input

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Problem

The Allegro Network Multimeter is connected to a Mirror or Packet Broker port. By default, this makes it difficult to analyze a specific link for bursts since the packets are aggregated on the Mirror or Packet Broker port.

Please note that this guide is based on the manual Burst analysis and on the use case guide Network Burst Analysis.

Link Burst Measurement

By default, the Allegro Network Multimeter measures the bursts per interface at L2 Ethernet Burst Analysis

Burst link measurement.png

Here you can configure the speed per link as the maximum speed. The percent values displayed are based on that maximum speed.

MAC Burst Measurement

To analyze a specific link, you can use the MAC burst analysis. This is shown in the second tab MACs in the burst analysis module. It allows you to set a specific receive and send bandwidth for a chosen MAC address. Up to five MAC addresses can be analyzed. If you have an uplink, simply use the Router´s MAC address here and then specify the maximum receive and send rate of the Router´s uplink.

In this example, we configured maximum values of 250MBit/s for the downlink and 40MBit/s for the uplink for the Router MAC address.

Burst mac measurement.png

Please note that the burst analysis is done with 1 millisecond resolution by default. In our example, the Router is connected at 1GBit/s and it can receive more than the configured uplink bandwidth. This is shown in the display as a utilization of ">> 100%" and indicates that a burst may not be able to be handled by this uplink.

Advantage for Mirror Port and Packet Brokers

The MAC burst detection can be used for a specific end device ( a file server,... ) or for the gateway of an uplink ( Router,... ). It allows to monitor links and end devices even in out-of-band installations.