netmon: An SNMP based network performance monitoring tool for packet data networks

In this paper we describe the design and features of netmon, a tool for performance monitoring of a packet data network. netmon continuously collects and stores SNMP variables by polling the backbone routers, netmon aims to estimate network performance statistics using this raw SNMP derived information. The measured estimate are link occupancies (in each direction), link up-times, bit error Fates on the links (in each direction), and mean packet waiting times at the router queues, netmon provides various command line options to view the above mentioned network statistics. We have tailored netmon to graphically display the reachability and other network statistics of the ERNET backbone (a nationwide network that connects various education and research institutions) on a vt ion terminal. Command line options are also provided for obtaining time series plots of these statistics for any specified time interval, as mail or a postcript file