rocap is an IP bandwidth monitoring system based on pcap.
rocap was designed to provide an easy way to monitor bandwidth between hosts, group of hosts or group of subnets, in any combination.
It was built for speed, rocap runs in user space with minimum CPU usage.
It includes a console server for telnet clients to use for administration or visualization purposes. It also outputs data for rrdtool to use for generating graphs.
roteq is free software.