User Commands                                            ETTCP(1)

NAME
     ettcp - test TCP and UDP performance

SYNOPSIS
     ettcp  -t  [-u]   [-s]   [-p port]   [-l buflen]   [-b size]
     [-n numbufs] [-A align] [-O offset] [-f format] [-i seconds]
     [-D] [-q] [-v] host [<in]
     ettcp  -r  [-u]   [-s]   [-p port]   [-l buflen]   [-b size]
     [-A align]  [-O offset]  [-f format]  [-i seconds] [-B] [-T]
     [-c] [-q] [-v] [>out]

DESCRIPTION
     Ettcp times the transmission and reception of  data  between
     two systems using the UDP or TCP protocols.  It differs from
     the original ttcp by the addition of several new features.

     For testing, the transmitter should be started with  -t  and
     -s  after  the  receiver  has  been  started with -r and -s.
     Tests lasting at least tens of seconds  should  be  used  to
     obtain  accurate  measurements.   Graphical presentations of
     throughput versus buffer size for buffers ranging from  tens
     of bytes to several ``pages'' can illuminate bottlenecks.

     Nttcp can also be used as  a  ``network  pipe''  for  moving
     directory  hierarchies between systems when routing problems
     exist or when the use of other  mechanisms  is  undesirable.
     For example, on the destination machine, use:  ettcp -r -B |
     tar xvpf -

     and on the source machine:  tar cf -  directory  |  ttcp  -t
     dest_machine

     Additional intermediate machines can be included by:   ettcp
     -r | ttcp -t next_machine

OPTIONS
     -t        Transmit mode.

     -r        Receive mode.

     -u        Use UDP instead of TCP.

     -s        If transmitting, source a data pattern to network;
               if  receiving,  sink  (discard) the data.  Without
               the -s option, the default  is  to  transmit  data
               from stdin or print the received data to stdout.

     -l length Length of buffers in bytes  (default  8192).   For
               UDP,  this  value  is  the number of data bytes in
               each packet.  The system limits  the  maximum  UDP
               packet  length. This limit can be changed with the
               -b option.

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User Commands                                            ETTCP(1)

     -b size   Set size of socket  buffer.   The  default  varies
               from system to system.  This parameter affects the
               maximum UDP packet length.  It may not be possible
               to  set  this parameter on some systems (for exam-
               ple, 4.2BSD).

     -n numbufs
               Number  of  source  buffers  transmitted  (default
               2048).

     -p port   Port number to  send  to  or  listen  on  (default
               2000).   On  some  systems, this port may be allo-
               cated to another network daemon.

     -D        If transmitting using TCP, do not buffer data when
               sending  (sets the TCP_NODELAY socket option).  It
               may not be possible to set this parameter on  some
               systems (for example, 4.2BSD).

     -B        When receiving  data,  output  only  full  blocks,
               using the block size specified by -l.  This option
               is useful  for  programs,  such  as  tar(1),  that
               require complete blocks.

     -A align  Align  the  start  of  buffers  to  this   modulus
               (default 16384).

     -O offset Align the start of buffers to this offset (default
               0).  For example, ``-A8192 -O1'' causes buffers to
               start at the second byte of an 8192-byte page.

     -f format Specify, using one of  the  following  characters,
               the  format  of  the  throughput rates as bits/sec
               ('b'),  bytes/sec   ('B'),   kilobits/sec   ('k'),
               kilobytes/sec     ('K'),    megabits/sec    ('m'),
               megabytes/sec  ('M'),   gigabits/sec   ('g'),   or
               gigabytes/sec  ('G').   raw bits/sec ('r'), or raw
               bytes/sec ('R').  The default is 'K'. "raw"  means
               that  only the numeric value is printed, without a
               unit of measure.

     -c        ``Collect call'' Used in conjunction with  the  -s
               and -r options. Initiate the connection, then read
               data from the remote host.

     -i seconds
               Test for the specified number of seonds.  Used  in
               conjunction  with  the  -s and -r options.  Rather
               than reading or  writing  a  specified  number  of
               buffers,  read  or write for a specified number of
               seconds. Useful when  the  network  speed  is  not
               known in advance, or may vary significantly.

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User Commands                                            ETTCP(1)

     -T        ``Touch'' the data as they are read  in  order  to
               measure cache effects.

     -q        Quiet: print only the measured network speed.

     -v        Verbose: print more statistics.

     -d        Debug: set the SO_DEBUG socket option.

SEE ALSO
     ping(8),  traceroute(8),  suck(1),  blow(1),   speedfrom(1),
     speedto(1)

ATTRIBUTES
     See attributes(5) for descriptions	of the following
     attributes:

     _______________________________________
    |	ATTRIBUTE TYPE	 |  ATTRIBUTE VALUE|
    |_______________________________________
    | Availability	 |  SUNWettcp	   |
    |_______________________________________
    | Interface	Stability|  Uncommitted	   |
    |____________________|_________________|

NOTES
     Source for	ettcp is available on http://opensolaris.org.