BWTest v0.72: Multi-connection bandwidth tester
Usage: BWTest [<options>] host1 [host2 [host3...]]]
  -p <num>    - Port number (default tcp:19=chargen, udp:7=echo)
  -i <sec>    - Plot interval in seconds
  -n <num>    - Initial number of streams.
  -d <kb>     - Kilobytes of data to transfer in each stream
  -r <num>    - Reconnect streams <num> times
  -m <num>    - Receive buffer multiplier (num*1460 bytes per recv() call)
  -l <ipaddr> - Local IP address
  -t <sec>    - Number of seconds to run
  -rrd        - Output rrd-style output

Running BWTest in UDP (RTT test) mode:
  -u <size> <num> - Send <num> packets per second, each <size> bytes
                    <size> includes IP and UDP headers, but not ethernet
                    The minimum value of <size> is 40
                    Note: size is presented PLUS ethernet in the display

  -ls         - Compute packet loss using strict sequence numbers
  -lt <ms>    - Packets later than n milliseconds are considered lost
  -a          - Sliding average adjustment smoothness: 2-200 [default 10]

Keyboard functions during test:
  [+]   - Increase number of streams
  [-]   - Decrease number of streams
  [*]   - UDP mode: Increase PPS
  [/]   - UDP mode: Decrease PPS
  Space - UDP mode: synch sliding averages with current totals

BWTest is a small bandwidth testing utility written
for development purposes by Clavister AB.

It simply connects to the chargen service in TCP mode,
or the echo service in UDP mode. Both these services
are available as built-in services in all inetd versions
under unix, and in the "Simple TCP/IP Services" service
under Windows NT. 

BWTest may talk to multiple hosts simultaneously, and open 
multiple connections to each host.

Example TCP test:
  > bwtest -n 16 host1 host2 host3 host4
  Will open four connections to four hosts, for a total
  of sixteen connections. The data rate is only limited
  by the sending chargen service and network units between
  said service and the workstation running bwtest.

Example UDP test:
  > bwtest -u 1500 500 -n 8 host1 host2 
  Will open four UDP connections to two hosts, for a total
  of eight connections. Each connection will send five hundred
  1500-byte packets each second, for an accumulated bandwidth
  of 8*500*1514*8 = 46.2Mbps.
  

In both modes, [+] and [-] may be pressed to increase or
decrease the number of open connections.

TCP mode is good for simulating "live" traffic.

UDP mode is good for determining packet loss and round trips
times. RTT is measured with 0.01ms granularity.