First let’s define what flow is. In packet switching networks, traffic flow, packet flow or network flow is a sequence of packets from a source computer to a destination, which may be another host, a multicast group, or a broadcast domain.
How flow is limited in TrafficInsights
Let’s assume there is no sampling. This corresponds to a sampling rate of 1 and no simulated sampling. By default, there is a rate limit of 500 flows/second. If the collector determines that a device is sending more flows than the limit, it will start dropping flows and mark the corresponding device as Limited.
What is Packet Sampling
Packet sampling is used to characterize network traffic. Packet sampling uses randomness in the sampling process to prevent synchronization with any periodic patterns in the traffic. While this type of packet sampling does not provide a 100% accurate result, it provides a result with quantifiable accuracy.
Packet sampling serves two purposes:
- Reducing the netflow overhead in the exporter device; for example in terms of CPU/Memory
- Reducing the flows sent to the flow collector (TrafficInsights)
Packet sampling allows Auvik to reduce the number of flows to be sent and later processed by TrafficInsights. As the packet sampling rate becomes higher, the fewer flows will be processed by TrafficInsights.
How to configure packet sampling rate
1. Click TrafficInsights in the side navigation bar.
2. Select Summary.
3. Search and select the desired device.
4. Click Sampling Rate.
5. Set the desired sampling rate from the drop-down box.
6. Select Yes or No to Apply as Simulated Sampling.
7. Click Save.