Allied Telesis AlliedWare Plus Operating System Version 5.4.4C (x310-26FT,x310-26FP,x310-50FT,x310-50FP) - Manual (Page 2083)

sFlow Introduction and Configuration
Software Reference for x310 Series Switches
C613-50046-01 REV A AlliedWare Plus TM Operating System - Version 5.4.4C 80.3
The sFlow Agent
Your switch can act as an sFlow agent. The key capabilities of the agent are to:
■ sample frames as they pass through selected ports on the switch, and provide
sampled extracts of the network traffic.
■ periodically capture interface counter data.
■ package together the sampled frame and counter information that can be sent to the
collector for analysis and display.
■ be configurable via SNMP MIB objects.
■ communicate to heterogeneous collector devices by means of standard protocols.
Agent components and functionality
sFlow functionality on your switch is based on the requirements defined in of RFC 3176
and its updates defined in the sFlow version 5 memo dated July 2004. This memo can be
found at the web site,
www.sflow.org/sflow_version_5.txt.
The terms defined in Table 80-1 are used to describe the agent and its functionality on
your switch:
The sFlow agent (switch) uses sampling technology to derive traffic statistics from its
monitored ports. Samples are taken at the sFlow source ports. After collecting its
information, the switch then packetizes its samples and statistical data, and sends both to
a remote sFlow collector.
Sampling Methods
Two sampling methods are employed within the sFlow agent, frame sampling, and
counter sampling. Both sample types are combined within the datagrams sent to the
collector. The frame sample data will result in a relatively constant traffic stream, but the
counter information is sent where it can fill available space within each datagram.
Datagrams are normally sent to the collector at the rate of one each second. However,
several datagrams can be sent in rapid succession, where more information exists than
can be sent in a single datagram.
Table 80-1: sFlow Terminology
sFlow® Component Definition
Network Device Typically either a network switch or router that has the
ability to forward frames across an Ethernet network; or
between Ethernet networks, in the case of a router.
Data Source
(sFlow Source Port) The location of a sampling point within the switch. This is
typically a switch port.
Packet Flow The path taken by the data (frames) as they traverse a
network device.
Sampling Rate The ratio of frames passing through the data source, to
those captured and forwarded as sFlow data.
See
sflow sampling-rate command on page 81.13 .
Counter Sampling The periodic polling of counters taken at the data source.
sFlow Datagram A UDP datagram that contains details of sFlow captured
data, and counters sent by the sFlow Agent to its Collector.