Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.02.xx and greater

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sFlow Agent
Configuring sFlow Using the Web Browser Interface
Figure 14-5. Flow Sampling Configuration Screen
4. From the Receiver Instance drop-down menu, choose the receiver index
number associated with the sFlow receiver to which the module should
send the samples.
To easily track which settings apply to a specific sFlow collector, match
the sFlow instance number to the receiver instance number. However,
matching the numbers is not mandatory. Although you can choose one
and only receiver for each flow, you can map multiple flows, even on the
same radio, to the same receiver. For example, you could map different
sFlow instances to the same receiver, but choose a different sampling rate
for the flows.
5. Enter a value between 50 and 65535 in the Packet Sampling Rate field.
The value determines how often the radio sends the sFlow agent a packet
to be sampled. In other words, the radio sends every “nth” packet, and “n”
is the value entered in the Packet Sampling Rate field. For example, if you
enter 100, the radio sends one percent of the packets to be sampled.
The accuracy of a sample increases as the absolute number of samples
increases. One general guideline is to set the rate so that the radio sends
about one sample per second. To determine the necessary rate, consider
roughly how much traffic the radio typically handles. For example, if the
radio handles about 1000 packets a second, you can set the rate to 1000.
On the other hand, if the radio, on average, handles only 100 packets a
second, it must sample traffic more frequently to achieve the same accu-
racy; set the rate to 100.