echoscu(1)                        OFFIS DCMTK                       echoscu(1)

NAME
       echoscu - DICOM verification (C-ECHO) SCU


SYNOPSIS
       echoscu [options] peer port

DESCRIPTION
       The  echoscu  application implements a Service Class User (SCU) for the
       Verification SOP Class. It sends a DICOM C-ECHO message  to  a  Service
       Class  Provider  (SCP) and waits for a response. The application can be
       used to verify basic DICOM connectivity.

PARAMETERS
       peer  hostname of DICOM peer

       port  tcp/ip port number of peer

OPTIONS
   general options
         -h    --help
                 print this help text and exit

               --version
                 print version information and exit

               --arguments
                 print expanded command line arguments

         -q    --quiet
                 quiet mode, print no warnings and errors

         -v    --verbose
                 verbose mode, print processing details

         -d    --debug
                 debug mode, print debug information

         -ll   --log-level  [l]evel: string constant
                 (fatal, error, warn, info, debug, trace)
                 use level l for the logger

         -lc   --log-config  [f]ilename: string
                 use config file f for the logger

   network options
       IP protocol version:

         -i4   --ipv4
                 use IPv4 only (default)

         -i6   --ipv6
                 use IPv6 only

         -i0   --ip-auto
                 use DNS lookup to determine IP protocol

       application entity titles:

         -aet  --aetitle  [a]etitle: string
                 set my calling AE title (default: ECHOSCU)

         -aec  --call  [a]etitle: string
                 set called AE title of peer (default: ANY-SCP)

       association negotiation debugging:

         -pts  --propose-ts  [n]umber: integer (1..53)
                 propose n transfer syntaxes

         -ppc  --propose-pc  [n]umber: integer (1..128)
                 propose n presentation contexts

       other network options:

         -to   --timeout  [s]econds: integer (default: unlimited)
                 timeout for connection requests

         -ts   --socket-timeout  [s]econds: integer (default: 60)
                 timeout for network socket (0 for none)

         -ta   --acse-timeout  [s]econds: integer (default: 30)
                 timeout for ACSE messages

         -td   --dimse-timeout  [s]econds: integer (default: unlimited)
                 timeout for DIMSE messages

         -pdu  --max-pdu  [n]umber of bytes: integer (4096..131072)
                 set max receive pdu to n bytes (default: 16384)

               --repeat  [n]umber: integer
                 repeat n times

               --abort
                 abort association instead of releasing it

   transport layer security (TLS) options
       transport protocol stack:

         -tls  --disable-tls
                 use normal TCP/IP connection (default)

         +tls  --enable-tls  [p]rivate key file, [c]ertificate file: string
                 use authenticated secure TLS connection

         +tla  --anonymous-tls
                 use secure TLS connection without certificate

       private key password (only with --enable-tls):

         +ps   --std-passwd
                 prompt user to type password on stdin (default)

         +pw   --use-passwd  [p]assword: string
                 use specified password

         -pw   --null-passwd
                 use empty string as password

       key and certificate file format:

         -pem  --pem-keys
                 read keys and certificates as PEM file (default)

         -der  --der-keys
                 read keys and certificates as DER file

       certification authority:

         +cf   --add-cert-file  [f]ilename: string
                 add certificate file to list of certificates

         +cd   --add-cert-dir  [d]irectory: string
                 add certificates in d to list of certificates

         +crl  --add-crl-file  [f]ilename: string
                 add certificate revocation list file
                 (implies --enable-crl-vfy)

         +crv  --enable-crl-vfy
                 enable leaf CRL verification

         +cra  --enable-crl-all
                 enable full chain CRL verification

       security profile:

         +ph   --list-profiles
                 list supported TLS profiles and exit

         +pg   --profile-8996
                 BCP 195 RFC 8996 TLS Profile (default)

         +pm   --profile-8996-mod
                 Modified BCP 195 RFC 8996 TLS Profile

                 # only available if underlying TLS library supports
                 # all TLS features required for this profile

         +py   --profile-bcp195-nd
                 Non-downgrading BCP 195 TLS Profile (retired)

         +px   --profile-bcp195
                 BCP 195 TLS Profile (retired)

         +pz   --profile-bcp195-ex
                 Extended BCP 195 TLS Profile (retired)

         +pb   --profile-basic
                 Basic TLS Secure Transport Connection Profile (retired)

                 # only available if underlying TLS library supports 3DES

         +pa   --profile-aes
                 AES TLS Secure Transport Connection Profile (retired)

         +pn   --profile-null
                 Authenticated unencrypted communication
                 (retired, was used in IHE ATNA)

       ciphersuite:

         +cc   --list-ciphers
                 list supported TLS ciphersuites and exit

         +cs   --cipher  [c]iphersuite name: string
                 add ciphersuite to list of negotiated suites

       server name indication:

               --no-sni
                 do not use SNI (default)

               --request-sni  [s]erver name: string
                 request server name s

       pseudo random generator:

         +rs   --seed  [f]ilename: string
                 seed random generator with contents of f

         +ws   --write-seed
                 write back modified seed (only with --seed)

         +wf   --write-seed-file  [f]ilename: string (only with --seed)
                 write modified seed to file f

       peer authentication:

         -rc   --require-peer-cert
                 verify peer certificate, fail if absent (default)

         -ic   --ignore-peer-cert
                 don't verify peer certificate

       offline certificate verification:

         +vc   --verify-cert  [f]ilename: string
                 verify certificate against CA settings

                 # Load a client certificate and check whether it would be accepted
                 # when received during a TLS handshake. Print result and exit.

         +rc   --is-root-cert  [f]ilename: string
                 check if certificate is self-signed root CA

                 # Load a client certificate and check whether it is a valid,
                 # self-signed root CA certificate. Print result and exit.

NOTES
   DICOM Conformance
       The echoscu application supports the following SOP Classes as an SCU:

       VerificationSOPClass                                1.2.840.10008.1.1

       By default, the echoscu application will  only  propose  this  transfer
       syntax:

       LittleEndianImplicitTransferSyntax                  1.2.840.10008.1.2

       If  the  --propose-ts  option  is used, the following transfer syntaxes
       will also be proposed, depending on  the  numeric  value  'n'  that  is
       passed to this option:

       LittleEndianExplicitTransferSyntax                  1.2.840.10008.1.2.1
       BigEndianExplicitTransferSyntax                     1.2.840.10008.1.2.2
       JPEGProcess1TransferSyntax                          1.2.840.10008.1.2.4.50
       JPEGProcess2_4TransferSyntax                        1.2.840.10008.1.2.4.51
       JPEGProcess3_5TransferSyntax                        1.2.840.10008.1.2.4.52
       JPEGProcess6_8TransferSyntax                        1.2.840.10008.1.2.4.53
       JPEGProcess7_9TransferSyntax                        1.2.840.10008.1.2.4.54
       JPEGProcess10_12TransferSyntax                      1.2.840.10008.1.2.4.55
       JPEGProcess11_13TransferSyntax                      1.2.840.10008.1.2.4.56
       JPEGProcess14TransferSyntax                         1.2.840.10008.1.2.4.57
       JPEGProcess15TransferSyntax                         1.2.840.10008.1.2.4.58
       JPEGProcess16_18TransferSyntax                      1.2.840.10008.1.2.4.59
       JPEGProcess17_19TransferSyntax                      1.2.840.10008.1.2.4.60
       JPEGProcess20_22TransferSyntax                      1.2.840.10008.1.2.4.61
       JPEGProcess21_23TransferSyntax                      1.2.840.10008.1.2.4.62
       JPEGProcess24_26TransferSyntax                      1.2.840.10008.1.2.4.63
       JPEGProcess25_27TransferSyntax                      1.2.840.10008.1.2.4.64
       JPEGProcess28TransferSyntax                         1.2.840.10008.1.2.4.65
       JPEGProcess29TransferSyntax                         1.2.840.10008.1.2.4.66
       JPEGProcess14SV1TransferSyntax                      1.2.840.10008.1.2.4.70
       RLELosslessTransferSyntax                           1.2.840.10008.1.2.5
       DeflatedExplicitVRLittleEndianTransferSyntax        1.2.840.10008.1.2.1.99
       JPEGLSLosslessTransferSyntax                        1.2.840.10008.1.2.4.80
       JPEGLSLossyTransferSyntax                           1.2.840.10008.1.2.4.81
       JPEG2000LosslessOnlyTransferSyntax                  1.2.840.10008.1.2.4.90
       JPEG2000TransferSyntax                              1.2.840.10008.1.2.4.91
       JPEG2000Part2MulticomponentImageComp.LosslessOnlyT. 1.2.840.10008.1.2.4.92
       JPEG2000Part2MulticomponentImageComp.TransferSyntax 1.2.804.10008.1.2.4.93
       MPEG2MainProfileAtMainLevelTransferSyntax           1.2.840.10008.1.2.4.100
       MPEG2MainProfileAtHighLevelTransferSyntax           1.2.840.10008.1.2.4.101
       MPEG4HighProfileLevel4_1TransferSyntax              1.2.840.10008.1.2.4.102
       MPEG4BDcompatibleHighProfileLevel4_1TransferSyntax  1.2.840.10008.1.2.4.103
       MPEG4HighProfileLevel4_2_For2DVideoTransferSyntax   1.2.840.10008.1.2.4.104
       MPEG4HighProfileLevel4_2_For3DVideoTransferSyntax   1.2.840.10008.1.2.4.105
       MPEG4StereoHighProfileLevel4_2TransferSyntax        1.2.840.10008.1.2.4.106
       HEVCMainProfileLevel5_1TransferSyntax               1.2.840.10008.1.2.4.107
       HEVCMain10ProfileLevel5_1TransferSyntax             1.2.840.10008.1.2.4.108
       FragmentableMPEG2MainProfileMainLevelTransferSyntax 1.2.840.10008.1.2.4.100.1
       FragmentableMPEG2MainProfileHighLevelTransferSyntax 1.2.840.10008.1.2.4.101.1
       FragmentableMPEG4HighProfileLevel4_1TransferSyntax  1.2.840.10008.1.2.4.102.1
       FragmentableMPEG4BDcompatibleHighProfileLevel4_1Tr. 1.2.840.10008.1.2.4.103.1
       FragmentableMPEG4HighProfileLevel4_2_For2DVideoTr.S 1.2.840.10008.1.2.4.104.1
       FragmentableMPEG4HighProfileLevel4_2_For3DVideoTr.S 1.2.840.10008.1.2.4.105.1
       FragmentableMPEG4StereoHighProfileLevel4_2TransferS 1.2.840.10008.1.2.4.106.1
       HighThroughputJPEG2000ImageCompressionLossless.Tr.S 1.2.840.10008.1.2.4.201
       HighThroughputJPEG2000RPCLImageCompressionLoss.Tr.S 1.2.840.10008.1.2.4.202
       HighThroughputJPEG2000ImageCompressionTransferSynt. 1.2.840.10008.1.2.4.203

LOGGING
       The  level  of  logging  output  of  the various command line tools and
       underlying libraries can be specified by the  user.  By  default,  only
       errors  and  warnings  are  written to the standard error stream. Using
       option --verbose also informational messages  like  processing  details
       are  reported.  Option  --debug  can be used to get more details on the
       internal activity, e.g. for debugging purposes.  Other  logging  levels
       can  be  selected  using option --log-level. In --quiet mode only fatal
       errors are reported. In such very severe error events, the  application
       will  usually  terminate.  For  more  details  on the different logging
       levels, see documentation of module 'oflog'.

       In case the logging output should be written to file  (optionally  with
       logfile  rotation),  to syslog (Unix) or the event log (Windows) option
       --log-config can be used.  This  configuration  file  also  allows  for
       directing  only  certain messages to a particular output stream and for
       filtering certain messages based on the  module  or  application  where
       they  are  generated.  An  example  configuration  file  is provided in
       <etcdir>/logger.cfg.

COMMAND LINE
       All command line tools  use  the  following  notation  for  parameters:
       square  brackets  enclose  optional  values  (0-1), three trailing dots
       indicate that multiple values are allowed (1-n), a combination of  both
       means 0 to n values.

       Command line options are distinguished from parameters by a leading '+'
       or  '-' sign, respectively. Usually, order and position of command line
       options are arbitrary (i.e. they  can  appear  anywhere).  However,  if
       options  are  mutually exclusive the rightmost appearance is used. This
       behavior conforms to the  standard  evaluation  rules  of  common  Unix
       shells.

       In  addition,  one  or more command files can be specified using an '@'
       sign as a prefix to the filename (e.g. @command.txt).  Such  a  command
       argument  is  replaced  by  the  content of the corresponding text file
       (multiple whitespaces are treated as a  single  separator  unless  they
       appear  between  two  quotation marks) prior to any further evaluation.
       Please note that a command file cannot contain  another  command  file.
       This  simple  but  effective  approach  allows  one to summarize common
       combinations of options/parameters and  avoids  longish  and  confusing
       command lines (an example is provided in file <datadir>/dumppat.txt).

EXIT CODES
       The  echoscu  utility  uses  the following exit codes when terminating.
       This enables the user to check  for  the  reason  why  the  application
       terminated.

   general
       EXITCODE_NO_ERROR                         0
       EXITCODE_COMMANDLINE_SYNTAX_ERROR         1

   input file errors
       EXITCODE_CANNOT_READ_INPUT_FILE          20 (*)
       EXITCODE_INVALID_INPUT_FILE              22

   output file errors
       EXITCODE_CANNOT_WRITE_OUTPUT_FILE        40 (*)

   network errors
       EXITCODE_CANNOT_INITIALIZE_NETWORK       60 (*)
       EXITCODE_ASSOCIATION_ABORTED             70

       (*)  Actually,  these codes are currently not used by echoscu but serve
       as a placeholder for the corresponding group of exit codes.

ENVIRONMENT
       The echoscu utility  will  attempt  to  load  DICOM  data  dictionaries
       specified  in the DCMDICTPATH environment variable. By default, i.e. if
       the  DCMDICTPATH  environment   variable   is   not   set,   the   file
       <datadir>/dicom.dic  will be loaded unless the dictionary is built into
       the application (default for Windows).

       The  default  behavior  should  be  preferred   and   the   DCMDICTPATH
       environment  variable  only used when alternative data dictionaries are
       required. The DCMDICTPATH environment variable has the same  format  as
       the  Unix  shell PATH variable in that a colon (':') separates entries.
       On Windows systems, a semicolon (';') is used as a separator. The  data
       dictionary  code  will  attempt  to  load  each  file  specified in the
       DCMDICTPATH environment variable. It is an error if no data  dictionary
       can be loaded.

COPYRIGHT
       Copyright  (C)  1994-2025  by OFFIS e.V., Escherweg 2, 26121 Oldenburg,
       Germany.

Version 3.7.0                   Mon Dec 15 2025                     echoscu(1)
