Background: Know: RMON definitions of good and bad, table indexing, GetNext request, NM, Prerequisites - session, octet, source, destination, Recognize:


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Visualisation of traffic matrices

matrix groupEdit

Traffic matrices record statistics about conversations between pairs of addresses.  One dimension of the matrix lists the sources, and the other lists the destinations, with entries in the matrix providing the statistic for communication from that source to that destination.  An example of traffic between nodes and the corresponding matrix is shown below.


Traffic flow and corresponding matrix, from

"conversation" here includes communication at any time, in contrast to Netflow which has separate records for each session of communication between two addresses.

Statistics recorded in the matrix:

  • The number of packets sent (both good and bad)
  • The number of octets sent
  • The number of errored (bad) packets

The statistics are recorded in two matrices:

  • matrixSDTable: indexed by source then destination
  • matrixDSTable: indexed by destination then source

Having two matrices with different indexing allows more efficient GetNext access when NM is concerned 
with a particular source (SD) or destination (DS)

See alsoEdit

Corresponding lecture slide

A separate page discusses the visualisation of traffic matrices

Netflow does distinguish traffic from different sessions between the same source/destination

How to configure Cisco routers to enable collection of matrix statistics