/usr/ports/net-mgmt/mrtg-ping-probe/ mrtg-ping-probe is a ping probe for MRTG 2.x. It is used to monitor the round trip time and packet loss to networked devices. MRTG uses its output to generate graphs visualizing minimum and maximum round trip times or packet loss.
/usr/ports/net-mgmt/smokeping SmokePing is a latency logging and graphing system. It consists of a daemon process which organizes the latency measurements and a CGI which presents the graphs.