echoscu(1) OFFIS DCMTK echoscu(1) # [NAME](#NAME) echoscu - DICOM verification (C-ECHO) SCU # [SYNOPSIS](#SYNOPSIS) ``` echoscu [options] peer port ``` # [DESCRIPTION](#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](#PARAMETERS) ``` peer hostname of DICOM peer port tcp/ip port number of peer ``` # [OPTIONS](#OPTIONS) ## [general 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](#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_layer_security_%28TLS%29_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](#NOTES) ## [DICOM Conformance](#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](#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](#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](#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](#general) ``` EXITCODE_NO_ERROR 0 EXITCODE_COMMANDLINE_SYNTAX_ERROR 1 ``` ## [input file errors](#input_file_errors) ``` EXITCODE_CANNOT_READ_INPUT_FILE 20 (*) EXITCODE_INVALID_INPUT_FILE 22 ``` ## [output file errors](#output_file_errors) ``` EXITCODE_CANNOT_WRITE_OUTPUT_FILE 40 (*) ``` ## [network errors](#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](#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) Copyright (C) 1994-2025 by OFFIS e.V., Escherweg 2, 26121 Oldenburg, Germany. Mon Dec 15 2025 Version 3.7.0 --- Document: echoscu(1) from dcmtk 3.7.0-r8 (Chainguard OS) Source: https://github.com/DCMTK/dcmtk