Bigboos - network monitoring system

Bigboos is a network monitoring system that pools devices based on
configuration. It is designed to allow mid-sized ISPs to monitor their
network and central offices whose branch offices are connected on T1 or
E1 lines to monitor their clients and branches. It is based on ICMP and
SNMP. A small customer database manager is included. It has the
capability to generate and manage trouble tickets, provides the current
status about devices being monitored, and generates downtime reports.

For more details visit - http://bigboos.sourceforge.net