RFC 2123 (rfc2123) - Page 3 of 34
Traffic Flow Measurement: Experiences with NeTraMet
Alternative Format: Original Text Document
RFC 2123 Traffic Flow Measurement March 1997
1.1 NeTraMet structure and development
The Traffic Flow Architecture document [1] describes four components:
- METERS, which are attached to the network at the points where
it is desired to measure the traffic,
- METER READERS, which read data from meters and store it for later
use,
- MANAGERS, which configure meters and control meter readers, and
- ANALYSIS APPLICATIONS, which process the data from meter readers
so as to produce whatever reports are required.
NeTraMet is a computer program which implements the Traffic Meter,
stores the measured flow data in memory, and provides an SNMP agent
so as to make it available to Meter Readers. The NeTraMet
distribution files include NeMaC, which is a combined Manager and
Meter Reader capable of managing an arbitrary number of meters, each
of which may be using its own rule set, and having its flow data
collected at its own specified intervals. The NeTraMet distribution
also includes several rudimentary Analysis Applications, allowing
users to produce simple plots from NeMaC's flow data files (fd_filter
and fd_extract) and to monitor - in real time - the flows at a remote
meter (nm_rc and nifty).
Since the first release the Traffic Meter MIB [2] has been both
improved and simplified. Significant changes have included better
ways to specify traffic flows (i.e. more actions and better control
structures for the Packet Matching Engine), and computed attributes
(class and kind). These changes have been prompted by operational
requirements at sites using NeTraMet, and have been tested
extensively in successive versions of NeTraMet.
NeTraMet is widely used to collect usage data for Internet Service
Providers. This is especially so in Australia and New Zealand, but
there are also active users at sites around the world, for example in
Canada, France, Germany and Poland.
NeTraMet is very useful as a tool for understanding exactly where
traffic is flowing in large networks. Since the Traffic Meters
perform considerable data reduction (as specified by their rule sets)
they significantly reduce the volume of data to be read by Meter
Readers. This characteristic makes NeTraMet particularly effective
for networks with many remote sites. An example of this (the
Kawaihiko network) is briefly described below.
Brownlee Informational