I.4 Networking

I.4.1 Implementation Model

I.4.1.1 Application Data Flow

Application Data Flow Diagram

Figure I.4.1-1. Application Data Flow Diagram


The WADO Service Application receives WADO requests from a remote AE. These requests may be either over the URI, WS or RS interfaces. It is associated with the local real-world activity "Retrieve Images". It converts these requests into internal lookup functions to find the matching SOP Instances. It then obtains these matching SOP Instances and composes a response back to the requesting remote AE.

I.4.1.2 Functional Definition of AEs

I.4.1.2.1 Functional Definition of WADO Service Application

The reception of a WADO request will activate the AE. An internal request is sent to the search capabilities of the EXAMPLE-WADO-SERVICE. This request is based upon the request parameters or the URL resource end point from the WADO request. The response is a list of all SOP instances stored on the EXAMPLE-PACS-ARCHIVE that match the request parameters. If there are no matching instances, the AE will indicate this in the WADO response. For all matching instances, the AE will utilize the internal image transfer request to obtain a copy of each instance. If the request was for retrieval of instances, these instances will be returned. If the request was for retrieval of rendered instances, then the AE will render each instance and return the rendered results.

I.4.2 AE Specifications

This AE complies with Chapter 6 in PS3.18 , specifications for WS, RS and URI access.

I.4.2.1 WADO-WS Specifications

I.4.2.1.1 WADO-WS Retrieve Imaging Document Set

Table I.4.2-1. WADO-WS Retrieve Imaging Document Set Specification

Parameter

Restrictions

Transfer Syntaxes Supported

Any transfer syntax supported by the hosting EXAMPLE-PACS-ARCHIVE

SOP Class Restrictions

Any SOP class supported by the hosting EXAMPLE-PACS-ARCHIVE

Size restriction

Any size supported by the hosting EXAMPLE-PACS-ARCHIVE

Anonymization

Supports the DICOM Basic Application Level Confidentiality Profile plus the Retain Patient Characteristics option.


I.4.2.1.2 WADO-WS Retrieve Rendered Imaging Document Set

Table I.4.2-3. WADO-WS Retrieve Rendered Imaging Documents Specification

Parameter

Restrictions

Transfer Syntaxes Supported

Restricted to transfer syntaxes supported by the hosting EXAMPLE-PACS-ARCHIVE

SOP Class Restrictions

Restricted to SOP classes supported by the hosting EXAMPLE-PACS-ARCHIVE

Size restriction

Restricted to sizes supported by the hosting EXAMPLE-PACS-ARCHIVE

Rendered formats available

Supports JPEG and PDF for IMAGE IODS, and PDF for non-IMAGE IODS.

Rows restrictions

Must be in range 16 - 32767

Columns restrictions

Must be in range 16 - 32767

Region restrictions

None

Window Center restrictions

None

Window Width restrictions

None

Image Quality restrictions

None

Anonymization

Supports the DICOM Basic Application Level Confidentiality Profile plus the Retain Patient Characteristics option.

Annotation restrictions

None

Compression available

JPEG

Other restrictions

None


I.4.2.1.3 WADO-WS Retrieve Imaging Document Set Metadata

Not supported

I.4.2.1.4 Connection Policies
I.4.2.1.4.1 General

All standard WS connection policies apply. There are no extensions for WS options.

I.4.2.1.4.2 Number of Connections

EXAMPLE-WADO-SERVICE limits the number of simultaneous WS requests. Additional requests will be queued after the TCP connection is accepted. When an earlier request completes, a pending request will proceed.

Table I.4.2-4. Number of WS Requests Supported

Maximum number of simultaneous WS requests

100 (configurable)


I.4.2.1.4.3 Asynchronous Nature

EXAMPLE-WADO-SERVICE does not support WS asynchronous response.

I.4.2.2 WADO-URI Specification

I.4.2.2.1 WADO-URI Retrieve Imaging Document Set

Table I.4.2-5. WADO-URI Retrieve Imaging Documents Specification

Parameter

Restrictions

Transfer Syntaxes Supported

Restricted to transfer syntaxes supported by the hosting EXAMPLE-PACS-ARCHIVE

SOP Class restrictions

Restricted to SOP classes supported by the hosting EXAMPLE-PACS-ARCHIVE

Size restriction

Restricted to sizes supported by the hosting EXAMPLE-PACS-ARCHIVE

Anonymization

Supports the DICOM Basic Application Level Confidentiality Profile plus the Retain Patient Characteristics option.


If the URI Retrieve specifies no transfer syntax that is supported by the archive, the SOP Instance will be returned using the Implicit VR Little Endian Transfer Syntax.

I.4.2.2.2 WADO-WS Retrieve Rendered Imaging Document Set

Table I.4.2-6. WADO-URI Retrieve Rendered Imaging Documents Specification

Parameter

Restrictions

Transfer Syntaxes Supported

Restricted to transfer syntaxes supported by the hosting EXAMPLE-PACS-ARCHIVE

SOP Class restrictions

Restricted to SOP classes supported by the hosting EXAMPLE-PACS-ARCHIVE

Size restriction

Restricted to sizes supported by the hosting EXAMPLE-PACS-ARCHIVE

Rendered formats available

Supports JPEG and PDF for IMAGE IODS, and PDF for non-IMAGE IODS.

Rows restrictions

Must be in range 16 - 32767

Columns restrictions

Must be in range 16 - 32767

Region restrictions

None

Window Center restrictions

Whole window must be in the range of image pixel values.

Window Width restrictions

Must be greater than 4 and whole window must be in the range of image pixel values.

Image Quality restrictions

None

Anonymization

Supports the DICOM Basic Application Level Confidentiality Profile plus the Retain Patient Characteristics option.

Annotation Restrictions

None

Compression available

JPEG

Other restrictions

None


I.4.2.2.3 WADO-URI Retrieve Imaging Document Set Metadata

Not supported.

I.4.2.2.4 Connection Policies
I.4.2.2.4.1 General

All URI connections are limited to HTTP GET requests. The EXAMPLE-WADO-SERVICE ignores all unknown HTTP header parameters.

I.4.2.2.4.2 Number of Connections

EXAMPLE-WADO-SERVICE limits the number of simultaneous HTTP connections.

Table I.4.2-7. Number of HTTP Requests Supported

Maximum number of simultaneous HTTP requests

100 (configurable)


I.4.2.2.4.3 Asynchronous Nature

EXAMPLE-WADO-SERVICE supports HTTP pipelined requests and responses.

I.4.2.3 WADO-RS Specifications

I.4.2.3.1 WADO-RS Retrieve Study

Table I.4.2.3-1. WADO-RS Retrieve Study

Options

Restrictions

Data Types Supported (Accept Type)

Restricted to application/dicom or application/octet-stream

Transfer Syntaxes Supported

(transfer-syntax Accept parameter)

Any Transfer Syntax supported by the hosting EXAMPLE-PACS-ARCHIVE

SOP Class Restrictions

Restricted to SOP classes supported by the hosting EXAMPLE-PACS-ARCHIVE

Size Restriction

Restricted to size supported by the hosting EXAMPLE-PACS-ARCHIVE


I.4.2.3.2 WADO-RS Retrieve Series

Table I.4.2.3-2. WADO-RS Retrieve Series

Options

Restrictions

Data Types Supported (Accept Type)

Restricted to application/dicom or application/octet-stream

Transfer Syntaxes Supported

(Transfer-syntax Accept parameter)

Any Transfer Syntax supported by the hosting EXAMPLE-PACS-ARCHIVE

SOP Class Restrictions

Restricted to SOP classes supported by the hosting EXAMPLE-PACS-ARCHIVE

Size Restriction

Restricted to size supported by the hosting EXAMPLE-PACS-ARCHIVE


I.4.2.3.3 WADO-RS Retrieve Instance

Table I.4.2.3-3. WADO-RS Retrieve Instance

Options

Restrictions

Data Types Supported (Accept Type)

Restricted to application/dicom or application/octet-stream

Transfer Syntaxes Supported

(Transfer-syntax Accept parameter)

Any Transfer Syntax supported by the hosting EXAMPLE-PACS-ARCHIVE

SOP Class Restrictions

Restricted to SOP classes supported by the hosting EXAMPLE-PACS-ARCHIVE

Size Restriction

Restricted to size supported by the hosting EXAMPLE-PACS-ARCHIVE


I.4.2.3.4 WADO-RS Retrieve Frames

Table I.4.2.3-4. WADO-RS Retrieve Frames

Options

Restrictions

Data Types Supported (Accept Type)

Restricted to application/octet-stream

Transfer Syntaxes Supported

(Transfer-syntax Accept parameter)

Any Transfer Syntax supported by the hosting EXAMPLE-PACS-ARCHIVE

SOP Class Restrictions

Restricted to Multi-Frame Image Objects as defined in PS3.3.

Size Restriction

Restricted to size supported by the hosting EXAMPLE-PACS-ARCHIVE


I.4.2.3.5 WADO-RS Retrieve Bulk Data

Table I.4.2.3-5. WADO-RS Retrieve Bulk Data

Options

Restrictions

Data Types Supported (Accept Type)

Restricted to application/octet-stream

Transfer Syntaxes Supported

(Transfer-syntax Accept parameter)

Any Transfer Syntax supported by the hosting EXAMPLE-PACS-ARCHIVE

SOP Class Restrictions

Restricted to SOP classes supported by the hosting EXAMPLE-PACS-ARCHIVE

Size Restriction

Restricted to size supported by the hosting EXAMPLE-PACS-ARCHIVE


I.4.2.3.6 WADO-RS Retrieve Metadata

Table I.4.2.3-6. WADO-RS Retrieve Metadata

Options

Restrictions

Data Types Supported (Accept Type)

Restricted to application/dicom+xml

Accept-Encoding

Restricted to gzip, deflate, or identity (the use of no transformation whatsoever). See W3C RFC 2616 Protocol Parameters Section 3.5 for more information (http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html).

SOP Class Restrictions

Restricted to SOP classes supported by the hosting EXAMPLE-PACS-ARCHIVE

Size Restriction

Restricted to size supported by the hosting EXAMPLE-PACS-ARCHIVE


I.4.2.3.7 Connection Policies
I.4.2.3.7.1 General

All standard RS connection policies apply. There are no extensions for RS options.

I.4.2.3.7.2 Number of Connections

EXAMPLE-WADO-SERVICE limits the number of simultaneous RS requests. Additional requests will be queued after the HTTP connection is accepted. When an earlier request completes, a pending request will proceed.

Table I.4.2.3-7. Number of Rs Requests Supported

Maximum number of simultaneous RS requests

100 (configurable)


I.4.2.3.7.3 Asynchronous Nature

EXAMPLE-WADO-SERVICE does not support RS asynchronous response.

I.4.3 Network Interfaces

I.4.3.1 Physical Network Interface

EXAMPLE-WADO-SERVICE uses the network interface from the hosting EXAMPLE-PACS-ARCHIVE. See its conformance claim for details.

I.4.3.2 Additional Protocols

EXAMPLE-WADO-SERVICE uses the network services from the hosting EXAMPLE-PACS-ARCHIVE. See its conformance claim for details.

I.4.3.3 IPv4 and IPv6 Support

This product supports both IPv4 and IPv6 connections.

I.4.4 Configuration

I.4.4.1 HTTP URI Interface

The EXAMPLE-WADO-SERVICE can be configured to respond on two ports, one for unprotected HTTP traffic and one for TLS protected traffic. The TLS port will refuse any connection from a system that is not recognized as authenticated by a known authority.

I.4.4.2 WS Interface

The EXAMPLE-WADO-SERVICE can be configured to respond on either one or two service endpoints. Each endpoint offers both of the services.

The WSDL file to be used by clients is made available at the location http://<servername>/EXAMPLE-WADO-SERVICE?WSDL.

I.4.4.3 RS Interface

The EXAMPLE-WADO-SERVICE can be configured to respond on two ports, one for unprotected HTTP traffic and one for TLS protected traffic. The TLS port will refuse any connection from a system that is not recognized as authenticated by a known authority.