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

14-4
sFlow Agent
Overview
Counter polling works with flow sampling to create a more comprehensive
picture of network traffic. The counters for total traffic supplement the more
detailed information collected for samples.
The sFlow agent obtains the counters by periodically polling radios. The agent
polls radios as needed to fill datagrams most efficiently. However, you can
configure the maximum time that can elapse before a radio must be polled.
sFlow Receiver
The sFlow receiver, which receives samples from agents all over the network,
combines and analyzes the samples to produce a picture of network activity.
This picture can be quite detailed. For example, the sFlow receiver can
determine not only how much traffic the Wireless Edge Services xl Module’s
RP radios are handling, but also which devices are contributing to that
traffic—and which are contributing most.
Capabilities vary among sFlow receivers; some uses for sFlow include:
■ establishing a baseline picture of network activity against which later
activity can be compared and analyzed for signs of security breaches
■ monitoring congestion and other Quality of Service (QoS) issues
■ auditing and billing for network usage
■ finding and diagnosing network problems
An sFlow receiver can effectively monitor a large network because sFlow’s
sampling techniques extract only the necessary data from the traffic streams
on each data source, consuming minimal device and network resources in the
process. This approach shifts the burden of data manipulation and analysis
from the sFlow agent to the sFlow receiver. In addition, the receiver can
generate an accurate picture of network traffic even when agents sample a
relatively small percentage of traffic.
An example of an sFlow receiver is ProCurve Manager Plus (PCM Plus).
Configuring sFlow Receiver Instances
As described above, an sFlow agent forwards datagrams to an sFlow receiver.
Each relationship between an agent and a receiver is called a receiver
instance. Often the receiver uses the SNMP protocol to contact the agent,
reserve a receiver instance, a configure sFlow. Alternatively, receiver
instances can be set up on the agent itself.