Some basic commands
crl_*
operate on raw network data (packet or cell)
common options to control duration of collection, BPF
filters, interval times, configuration files, snaplen,
debugging levels, etc
crl_print_pkt
ASCII output (sortof like tcpdump)
crl_rate
packet and byte counts and rates (IPv4, IPv6, non-IP)
outputs at regular intervals
handles ATM VP:VCs, vlans, multiple interfaces