The cnupm is an IP/IPv6 traffic collector daemon; it listens on a network
interface for IP/IPv6 packets that match the boolean expression (see
tcpdump(8) for more information) and collects the following statistics:

     o   address family (INET/INET6)
     o   IP/IPv6 protocol number
     o   source IP/IPv6 address
     o   source TCP/UDP port
     o   destination IP/IPv6 address
     o   destination TCP/UDP port
     o   total number of bytes trasferred

WWW: http://pdp-11.org.ru/~form/cnupm