W3C

Web Services Addressing 1.0 - Metadata

W3C Recommendation 4 September 2007

This version:
http://www.w3.org/TR/2007/REC-ws-addr-metadata-20070904
Latest version:
http://www.w3.org/TR/ws-addr-metadata
Previous version:
http://www.w3.org/TR/2007/PR-ws-addr-metadata-20070731
Editors:
Martin Gudgin, Microsoft Corp
Marc Hadley, Sun Microsystems, Inc.
Tony Rogers, CA, Inc.
Ümit Yalçinalp, SAP AG

Please refer to the errata for this document, which may include some normative corrections.

This document is also available in these non-normative formats: PDF, PostScript, XML, and plain text.

See also translations.


Abstract

Web Services Addressing provides transport-neutral mechanisms to address Web services and messages. Web Services Addressing 1.0 - Metadata (this document) defines how the abstract properties defined in Web Services Addressing 1.0 - Core are described using WSDL, how to include WSDL metadata in endpoint references, and how WS-Policy can be used to indicate the support of WS-Addressing by a Web service.

Status of this Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.

This is the W3C Recommendation of Web Services Addressing 1.0 - Metadata specification for review by W3C members and other interested parties. It has been produced by the Web Services Addressing Working Group, which is part of the W3C Web Services Activity.

Please send comments on this document to the public public-ws-addressing-comments@w3.org mailing list (public archive).

The Working Group released a test suite along with an implementation report. A diff-marked version against the previous version of this document is available.

This document has been reviewed by W3C Members, by software developers, and by other W3C groups and interested parties, and is endorsed by the Director as a W3C Recommendation. It is a stable document and may be used as reference material or cited from another document. W3C's role in making the Recommendation is to draw attention to the specification and to promote its widespread deployment. This enhances the functionality and interoperability of the Web.

This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

Table of Contents

1. Introduction
    1.1 Notational Conventions
    1.2 Namespaces
2. Including WSDL Metadata in EPRs
    2.1 Referencing WSDL Metadata from an EPR
3. Indicating Use of WS-Addressing
    3.1 WS-Policy Assertions
        3.1.1 Addressing Assertion
        3.1.2 AnonymousResponses Assertion
        3.1.3 NonAnonymousResponses Assertion
        3.1.4 Examples (Compact Form)
        3.1.5 Examples (Normal Form)
        3.1.6 Finding Compatible Policies
4. Specifying Message Addressing Properties in WSDL
    4.1 Extending WSDL Endpoints with an EPR
        4.1.1 WSDL 2.0 Component Model Changes
    4.2 Destination
    4.3 Reference Parameters
    4.4 Action
        4.4.1 Explicit Association
        4.4.2 Default Action Pattern for WSDL 2.0
        4.4.3 WSDL 2.0 Component Model Changes
        4.4.4 Default Action Pattern for WSDL 1.1
5. WS-Addressing and WSDL Message Exchange Patterns
    5.1 WSDL 1.1 Message Exchange Patterns
        5.1.1 One-way
        5.1.2 Request-Response
        5.1.3 Notification
        5.1.4 Solicit-response
    5.2 WSDL 2.0 Message Exchange Patterns
        5.2.1 In-only
        5.2.2 Robust In-only
        5.2.3 In-out
        5.2.4 In-optional-out
        5.2.5 Out-only
        5.2.6 Robust Out-only
        5.2.7 Out-in
        5.2.8 Out-optional-in
6. Conformance
7. References
    7.1 Normative
    7.2 Informative

Appendices

A. Acknowledgements (Non-Normative)
B. Compatibility of [action] with previous versions of WS-Addressing (Non-Normative)


1. Introduction

Web Services Addressing 1.0 - Core [WS-Addressing Core] defines a set of abstract properties and an XML Infoset [XML Information Set] representation of Web service endpoint references (EPRs) and to facilitate end-to-end addressing of endpoints in messages. Web Services Addressing 1.0 - Metadata (this document) defines how the abstract properties defined in Web Services Addressing 1.0 - Core are described using WSDL and how WS-Policy can be used to indicate the support of WS-Addressing by a Web service. WS-Addressing is designed to be able to work with WS-Policy 1.5 [WS Policy 1.5], WSDL 2.0 [WSDL 2.0] and also (for backwards compatibility) with WSDL 1.1 [WSDL 1.1] described services.

1.1 Notational Conventions

The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [IETF RFC 2119].

When describing abstract data models, this specification uses the notational convention used by the XML Infoset [XML Information Set]. Specifically, abstract property names always appear in square brackets (e.g., [some property]).

When describing concrete XML schemas [XML Schema Structures, XML Schema Datatypes], this specification uses the notational convention of WS-Security [WS-Security]. Specifically, each member of an element's [children] or [attributes] property is described using an XPath-like notation (e.g., /x:MyHeader/x:SomeProperty/@value1). The use of {any} indicates the presence of an element wildcard (<xs:any/>). The use of @{any} indicates the presence of an attribute wildcard (<xs:anyAttribute/>).

1.2 Namespaces

This specification uses a number of namespace prefixes throughout; they are listed in Table 1-1. Note that the choice of any namespace prefix is arbitrary and not semantically significant (see [XML Namespaces]).

Table 1-1. Prefixes and Namespaces used in this specification
Prefix Namespace
S http://www.w3.org/2003/05/soap-envelope
S11 http://schemas.xmlsoap.org/soap/envelope
wsa http://www.w3.org/2005/08/addressing
wsam http://www.w3.org/2007/05/addressing/metadata
wsoap http://www.w3.org/ns/wsdl/soap
xs http://www.w3.org/2001/XMLSchema
wsdl Either http://www.w3.org/ns/wsdl or http://schemas.xmlsoap.org/wsdl/ depending on context
wsdl20 http://www.w3.org/ns/wsdl
wsdl11 http://schemas.xmlsoap.org/wsdl/
soap11 http://schemas.xmlsoap.org/wsdl/soap/
wsp http://www.w3.org/ns/ws-policy

The working group intends to update the value of the Web Services Addressing 1.0 - Metadata namespace URI each time a new version of this document is published until such time that the document reaches Candidate Recommendation status. Once it has reached Candidate Recommendation status, the working group intends to maintain the value of the Web Services Addressing 1.0 - Metadata namespace URI that was assigned in the Candidate Recommendation unless significant changes are made that impact the implementation of the specification.

WS-Addressing is defined in terms of the XML Information Set [XML Information Set]. WS-Addressing can be used with SOAP [SOAP 1.2, SOAP 1.1] as described in Web Services Addressing 1.0 - SOAP Binding [WS-Addressing SOAP Binding]. The examples in this specification use an XML 1.0 [XML 1.0] representation but this is not a requirement.

All information items defined by this specification are identified by the XML namespace URI [XML Namespaces] "http://www.w3.org/2007/05/addressing/metadata". A normative XML Schema [XML Schema Structures, XML Schema Datatypes] document can be obtained by dereferencing the XML namespace URI.

2. Including WSDL Metadata in EPRs

An EPR's metadata section can contain a reference to WSDL metadata, can include embedded WSDL metadata, or both.

2.1 Referencing WSDL Metadata from an EPR

The WSDL binding of Web Services Addressing introduces the following element and attribute information items for referencing WSDL metadata from an EPR's metadata section:

wsam:InterfaceName (0..1)

A QName identifying a description of the sequences of messages that a service sends and/or receives. This corresponds to a WSDL 2.0 interface or, for backwards compatibility, a WSDL 1.1 port type. When this element is included in an EPR, the EPR is considered to be specific to the interface or port type it identifies.

wsam:ServiceName (0..1)

A QName that identifies the set of endpoints at which a particular Web service is deployed. The set of endpoints is represented by a service in WSDL 2.0 or, for backwards compatibility, a WSDL 1.1 service.

wsam:ServiceName/@EndpointName (0..1)

An NCName that identifies one endpoint amongst the set identified by the service name above. An endpoint is represented by an endpoint in WSDL 2.0 or, for backwards compatibility, a port in WSDL 1.1. When this attribute is specified, the EPR is considered to be specific to the endpoint or port it identifies.

The element information items defined above are used in an EPR's metadata section. The following shows an example endpoint reference. This references the interface named "ghns:reservationInterface" at the endpoint IRI "http://greath.example.com/2004/reservation". Note the use of the WSDL[WSDL 2.0] wsdlLocation attribute.

Example 2-1. Example endpoint reference.

<wsa:EndpointReference
    xmlns:wsa="http://www.w3.org/2005/08/addressing"
    xmlns:ghns="http://greath.example.com/2004/wsdl/resSvc">
  <wsa:Address>http://greath.example.com/2004/reservation</wsa:Address>
  <wsa:Metadata
      xmlns:wsdli="http://www.w3.org/ns/wsdl-instance"
      wsdli:wsdlLocation="http://greath.example.com/2004/wsdl/resSvc http://greath.example.com/2004/reservation.wsdl">
    <wsam:InterfaceName>ghns:reservationInterface</wsam:InterfaceName>
  </wsa:Metadata>
</wsa:EndpointReference>

3. Indicating Use of WS-Addressing

This specification supports a mechanism for indicating, in a WSDL description, that the endpoint conforms to the WS-Addressing specification. That mechanism uses WS-Policy Framework [WS Policy 1.5].

3.1 WS-Policy Assertions

The mechanism for indicating that a binding or endpoint conforms to the WS-Addressing specification is through the use of the Web Services Policy - Framework [WS Policy 1.5] and Web Services Policy - Attachment [WS Policy 1.5 - Attachment] specifications. This specification defines three policy assertions.

The wsam:Addressing policy assertion applies to the endpoint policy subject.

For WSDL 1.1, these assertions may be attached to wsdl11:port or wsdl11:binding. For WSDL 2.0, they may be attached to wsdl20:endpoint or wsdl20:binding. A policy expression containing the wsam:Addressing policy assertion MUST NOT be attached to a wsdl:portType or wsdl20:interface. The wsam:Addressing policy assertion specifies a concrete behavior whereas the wsdl:portType or wsdl20:interface is an abstract construct.

3.1.1 Addressing Assertion

The wsam:Addressing policy assertion is a nested policy container assertion. The meaning of this assertion, when present in a policy alternative, is that WS-Addressing is required to communicate with the subject. The wsam:Addressing assertion indicates that there are no restrictions on the use of WS-Addressing unless otherwise qualified by assertions in its nested policy expression. In order to indicate that the subject supports WS-Addressing but does not require its use, an additional policy alternative should be provided which does not contain this assertion; the compact authoring style for an optional policy assertion provided by WS-Policy V1.5 [WS Policy 1.5] may be used. The wsp:Optional attribute, as a syntactic shortcut, can be used with the wsam:Addressing assertion. This indicates two policy alternatives, one which contains the policy assertion, and another which does not.

The inclusion of this assertion implies support for the Web Services Addressing 1.0 - Core [WS-Addressing Core] and Web Services Addressing 1.0 - SOAP Binding [WS-Addressing SOAP Binding].

3.1.2 AnonymousResponses Assertion

The wsam:AnonymousResponses element MAY be used as a policy assertion nested within the wsam:Addressing assertion in accordance with the rules laid down by policy assertion nesting ([WS Policy 1.5], section 4.3.2).

The appearance of this element within the wsam:Addressing policy assertion indicates that the endpoint requires request messages to use response endpoint EPRs that contain the anonymous URI ("http://www.w3.org/2005/08/addressing/anonymous") as the value of [address]. In other words, the endpoint requires the use of anonymous responses.

The None URI ("http://www.w3.org/2005/08/addressing/none") may appear as the value of [address] in place of the anonymous URI; this value MUST be accepted.

3.1.3 NonAnonymousResponses Assertion

The wsam:NonAnonymousResponses element MAY be used as a policy assertion nested within the Addressing assertion in accordance with the rules laid down by policy assertion nesting ([WS Policy 1.5], section 4.3.2). The wsam:NonAnonymousResponses policy assertion MUST NOT be used in the same policy alternative as the wsam:AnonymousResponses policy assertion.

The appearance of this element within the wsam:Addressing assertion indicates that the endpoint expresses requires request messages to use response endpoint EPRs that contain something other than the anonymous URI as the value of [address]. In other words, the endpoint requires the use of non-anonymous responses. This assertion is deliberately vague; its presence indicates that some non-anonymous addresses will be accepted but doesn't constrain what such an address might look like. A receiver can still reject a request that contains an address that it doesn't understand or that requires a binding it doesn't support.

The None URI ("http://www.w3.org/2005/08/addressing/none") may appear as the value of [address] in place of a non-anonymous address; this value MUST be accepted.

3.1.4 Examples (Compact Form)

Example 3-1. Subject supports WS-Addressing

<wsp:Policy>
    <wsam:Addressing wsp:Optional="true">
        <wsp:Policy/>
    </wsam:Addressing>
</wsp:Policy>

Example 3-2. Subject requires WS-Addressing

<wsp:Policy>
    <wsam:Addressing>
        <wsp:Policy/>
    </wsam:Addressing>
</wsp:Policy>

Example 3-3. Subject requires WS-Addressing and requires the use of non-anonymous response EPRs

<wsp:Policy>
    <wsam:Addressing>
        <wsp:Policy>
            <wsam:NonAnonymousResponses/>
        </wsp:Policy>
    </wsam:Addressing>
</wsp:Policy>

3.1.5 Examples (Normal Form)

Example 3-4. Subject supports WS-Addressing

<wsp:Policy>
    <wsp:ExactlyOne>
        <wsp:All/>
        <wsp:All>
            <wsam:Addressing>
                <wsp:Policy>
                    <wsp:ExactlyOne>
                        <wsp:All/>
                    </wsp:ExactlyOne>
                </wsp:Policy>
            </wsam:Addressing>
        </wsp:All>
    </wsp:ExactlyOne>
</wsp:Policy>

Example 3-5. Subject requires WS-Addressing

<wsp:Policy>
    <wsp:ExactlyOne>
        <wsp:All>
            <wsam:Addressing>
                <wsp:Policy>
                    <wsp:ExactlyOne>
                        <wsp:All/>
                    </wsp:ExactlyOne>
                </wsp:Policy>
            </wsam:Addressing>
        </wsp:All>
    </wsp:ExactlyOne>
</wsp:Policy>

Example 3-6. Subject requires WS-Addressing and requires the use of non-anonymous response EPRs

<wsp:Policy>
    <wsp:ExactlyOne>
        <wsp:All>
            <wsam:Addressing>
                <wsp:Policy>
                    <wsp:ExactlyOne>
                        <wsp:All>
                            <wsam:NonAnonymousResponses/>
                        </wsp:All>
                    </wsp:ExactlyOne>
                </wsp:Policy>
            </wsam:Addressing>
        </wsp:All>
    </wsp:ExactlyOne>
</wsp:Policy>

3.1.6 Finding Compatible Policies

When a client is looking for an endpoint with compatible policy, one common method used is to take the policy intersection between the policy which the client is looking for, and the policy asserted in the WSDL document; a non-empty intersection is sought. The policy used by the client must be written carefully to avoid unexpected results. This is most obvious when the client is not looking for explicit support of a particular kind of response; failing to take care could mean missing a compatible policy.

Example 3-7. Client looking for an endpoint which supports Addressing, and which supports anonymous responses

<wsp:Policy>
    <wsp:ExactlyOne>
        <wsp:All>
            <wsam:Addressing>
                <wsp:Policy>
                    <wsp:ExactlyOne>
                        <wsp:All>
                            <AnonymousResponses Optional=”true”/>
                        </wsp:All>
                    </wsp:ExactlyOne>
                </wsp:Policy>
            </wsam:Addressing>
        </wsp:All>
    </wsp:ExactlyOne>
</wsp:Policy>

Example 3-8. Client looking for an endpoint which supports Addressing, and does not require support for responses (will intersect with anything)

<wsp:Policy>
    <wsp:ExactlyOne>
        <wsp:All>
            <wsam:Addressing> <-- supports all response types -->
                <wsp:Policy>
                </wsp:Policy>
            </wsam:Addressing>
        </wsp:All>
        <wsp:All>
            <wsam:Addressing> <-- requires Anonymous responses -->
                <wsp:Policy>
                    <wsp:ExactlyOne>
                        <wsp:All>
                            <AnonymousResponses />
                        </wsp:All>
                    </wsp:ExactlyOne>
                </wsp:Policy>
            </wsam:Addressing>
        </wsp:All>
        <wsp:All>
            <wsam:Addressing> <-  requires nonAnonymous responses -->
                <wsp:Policy>
                    <wsp:ExactlyOne>
                        <wsp:All>
                            <NonAnonymousResponses />
                        </wsp:All>
                    </wsp:ExactlyOne>
                </wsp:Policy>
            </wsam:Addressing>
        </wsp:All>
    </wsp:ExactlyOne>
</wsp:Policy>

For more detailed descriptions of the use of wsp:Optional, wsp:Ignorable, and strict and lax intersection, please refer to the WS-Policy Primer [WS Policy 1.5 - Primer].

4. Specifying Message Addressing Properties in WSDL

This section describes how the values of certain message addressing properties can be specified in WSDL. In some cases the values of message addressing properties are specified using existing WSDL constructs, in other cases new WSDL extensions are defined for that purpose.

4.1 Extending WSDL Endpoints with an EPR

A wsdl20:endpoint or wsdl11:port element MAY be extended using a child wsa:EndpointReference element. When extended this way, the [address] property of the child EPR MUST match the {address} property of the endpoint component (WSDL 2.0) or the address value provided by the relevant port extension (WSDL 1.1). For example, in a SOAP 1.1 port described using WSDL 1.1, the location attribute of a soap11:address element (if present) would have the same value as the wsa:Address child element of the wsa:EndpointReference element.

4.1.1 WSDL 2.0 Component Model Changes

Use of WS-Addressing adds the following OPTIONAL properties to the WSDL 2.0 component model:

  • A property of the Endpoint component, named {endpoint reference}. This property is of type wsa:EndpointReference, with a cardinality of 1. The property has the value of the wsa:EndpointReference element used as a child of wsdl20:endpoint, if any. If no such extension exists, this property is absent.

4.2 Destination

The value of the [destination] message addressing property for a message sent to an endpoint typically matches the value of the {address} property of the endpoint component (WSDL 2.0) or the address value (if any) provided by the relevant port extension (WSDL 1.1). For a SOAP 1.1 port described using WSDL 1.1, the value is provided by the location attribute of the soap11:address extension element. For an endpoint or port extended with an EPR (see 4.1 Extending WSDL Endpoints with an EPR), the value is provided by the [address] property of the EPR.

Additional runtime information could override the value of the [destination] message addressing property for messages sent to an endpoint, e.g. a runtime exchange might result in a redirection to a different EPR. Note that WS-Addressing does not define any normative mechanism for such redirection.

4.3 Reference Parameters

When a wsa:EndpointReference element is present in a wsdl20:endpoint or a wsdl11:port element (see 4.1 Extending WSDL Endpoints with an EPR), the value of the [reference parameters] message addressing property for a message sent to an endpoint MUST include the contents of the wsa:ReferenceParameters element, if one exists within that EPR.

4.4 Action

WS-Addressing defines two mechanisms to associate a value of the [action] property with input, output and fault elements within a WSDL description: explicit and defaulting. Explicit association is described in section 4.4.1 Explicit Association; action defaulting (where a unique value for the [action] property is automatically generated) is described in section 4.4.4 Default Action Pattern for WSDL 1.1 for WSDL 1.1 and section 4.4.2 Default Action Pattern for WSDL 2.0 for WSDL 2.0.

Ensuring that there is sufficient information within a message to distinguish which WSDL operation it is associated with is specified as a best practice in WSDL 2.0WSDL 2.0. The [action] property provides a mechanism to fulfill that best practice.

4.4.1 Explicit Association

WS-Addressing defines a global attribute, wsam:Action, that can be used to explicitly define the value of the [action] property for messages in a WSDL description. The type of the attribute is xs:anyURI and it is used as an extension on the WSDL input, output and fault elements. A SOAP binding can specify SOAPAction values for the input messages of operations. In the absence of a wsam:Action attribute on a WSDL input element where a non-empty SOAPAction value is specified, the value of the [action] property for the input message is the value of the SOAPAction specified. If the wsam:Action attribute is absent, and SOAPAction is not specified, or is empty, then the default pattern is used. Note that the SOAPAction value is not required to be an absolute IRI, but the [action] property is required to be an absolute IRI; if WS-Addressing is required (the wsam:Addressing assertion is present), wsam:Action is not specified, and the SOAPAction value is not empty or an absolute IRI, then the document MUST be considered invalid. Web Services Addressing 1.0 - SOAP Binding[WS-Addressing SOAP Binding] specifies restrictions on the relationship between the values of [action] and SOAPAction for SOAP 1.1 and SOAP 1.2.

The inclusion of wsam:Action without the inclusion of the wsam:Addressing assertion has no normative intent and is only informational. In other words, the inclusion of wsam:Action attributes in WSDL alone does not imply a requirement on clients to use Message Addressing Properties in messages it sends to the service. A client, however, MAY include Message Addressing Properties in the messages it sends, either on its own initiative or as described by other elements of the service contract, regardless of the presence or absence of the wsam:Addressing assertion. Other specifications defining the value of [action] are under no constraint to be consistent with wsam:Action.

For example consider the following WSDL excerpt:

Example 4-1. Explicit specification of wsa:Action value in a WSDL 2.0 description.

<description targetNamespace="http://greath.example.com/2004/schemas/resSvc" ...>
  ...
  <interface name="reservationInterface">
    <operation name="opCheckAvailability" pattern="http://www.w3.org/ns/wsdl/in-out">
      <input element="tns:checkAvailability" messageLabel="In"
            wsam:Action="http://greath.example.com/2004/wsdl/resSvc/opCheckAvailability"/>
      <output element="tns:checkAvailabilityResponse" messageLabel="Out"
            wsam:Action="http://greath.example.com/2004/wsdl/resSvc/opCheckAvailabilityResponse"/>
    </operation>
  </interface>
  ...
</description>

The action for the input of the opCheckAvailability operation within the reservationInterface is explicitly defined to be http://greath.example.com/2004/wsdl/resSvc/opCheckAvailability. The action for the output of this same operation is http://greath.example.com/2004/wsdl/resSvc/opCheckAvailabilityResponse.

Example 4-2. Explicit specification of wsa:Action value in a WSDL 1.1 description.

<definitions targetNamespace="http://greath.example.com/2004/schemas/resSvc" ...>
  ...
  <portType name="reservationInterface">
    <operation name="opCheckAvailability">
      <input message="tns:checkAvailability"
            wsam:Action="http://greath.example.com/2004/wsdl/resSvc/opCheckAvailability"/>
      <output message="tns:checkAvailabilityResponse"
            wsam:Action="http://greath.example.com/2004/wsdl/resSvc/opCheckAvailabilityResponse"/>
    </operation>
  </portType>
  ...
</definitions>
      

The action for the input of the opCheckAvailability operation within the reservationInterface port type is explicitly defined to be http://greath.example.com/2004/wsdl/resSvc/opCheckAvailability. The action for the output of this same operation is http://greath.example.com/2004/wsdl/resSvc/opCheckAvailabilityResponse.

4.4.2 Default Action Pattern for WSDL 2.0

In the absence of an explicitly specified value for the [action] property (see section 4.4.1 Explicit Association), the following pattern is used in WSDL 2.0 documents to construct a default action for inputs and outputs. The general form of an action URI is as follows:

Example 4-3. Structure of defaulted wsa:Action IRI in WSDL 2.0.

[target namespace][delimiter][interface name][delimiter][operation name][direction token]

For fault messages, the general form of an action IRI is as follows:

Example 4-4. Structure of default wsa:Action IRI for faults

[target namespace][delimiter][interface name][delimiter][operation name][direction token][delimiter][fault name]

Where:

[delimiter]

is ":" when the [target namespace] is a URN, otherwise "/". Note that for IRI schemes other than URNs which aren't path-based (i.e. those that outlaw the "/" character), the default action value might not conform to the rules of the IRI scheme. Authors are advised to specify explicit values in the WSDL in this case.

[target namespace]

is the {target namespace} of the interface. If [target namespace] ends with a "/" an additional "/" is not added.

[interface name]

is the {name} of the interface.

[operation name]

is the {name} of the operation.

[fault name]

is the {name} of the fault.

[direction token]
  • Empty ("") where the operation's {message exchange pattern} is "http://www.w3.org/ns/wsdl/in-only", "http://www.w3.org/ns/wsdl/robust-in-only", "http://www.w3.org/ns/wsdl/out-only", or "http://www.w3.org/ns/wsdl/robust-out-only".

  • "Request" where the operation's {message exchange pattern} is "http://www.w3.org/ns/wsdl/in-out" or "http://www.w3.org/ns/wsdl/in-opt-out" and the message reference's {message label} = 'In'.

  • "Solicit" where the operation's {message exchange pattern} is "http://www.w3.org/ns/wsdl/out-in" or "http://www.w3.org/ns/wsdl/out-opt-in" and the message reference's {message label} = 'Out'.

  • "Response" where the operation's {message exchange pattern} is "http://www.w3.org/ns/wsdl/in-out" or "http://www.w3.org/ns/wsdl/in-opt-out" and the message reference's {message label} = 'Out'.

  • "Response" where the operation's {message exchange pattern} is "http://www.w3.org/ns/wsdl/out-in", or "http://www.w3.org/ns/wsdl/out-opt-in" and the message reference's {message label} = 'In'.

  • {message label} where the {message exchange pattern} is not one of the MEP IRIs defined in WSDL 2.0 Part 2.

For example consider the following WSDL excerpt:

Example 4-5. Example WSDL without explicit wsa:Action values.

<description targetNamespace="http://greath.example.com/2004/wsdl/resSvc" ...>
  ...
  <interface name="reservationInterface">
    <operation name="opCheckAvailability" pattern="http://www.w3.org/ns/wsdl/in-out">
      <input element="tns:checkAvailability" messageLabel="In"/>
      <output element="tns:checkAvailabilityResponse" messageLabel="Out"/>
    </operation>
  </interface>
  ...
</definitions>
      

[targetNamespace] = http://greath.example.com/2004/wsdl/resSvc

[interface name] = reservationInterface

[operation name] = opCheckAvailability

[direction token] for input is Request

[direction token] for output is Response

Applying the patterns above with these values we have:

input action = http://greath.example.com/2004/wsdl/resSvc/reservationInterface/opCheckAvailabilityRequest

output action = http://greath.example.com/2004/wsdl/resSvc/reservationInterface/opCheckAvailabilityResponse

fault action for a fault named AvailabilityNotAvailableFault = http://greath.example.com/2004/wsdl/resSvc/reservationInterface/opCheckAvailabilityResponse/AvailabilityNotAvailableFault

4.4.3 WSDL 2.0 Component Model Changes

Use of WS-Addressing adds the following REQUIRED properties to the WSDL 2.0 component model:

  • A property of the Interface Message Reference and Interface Operation InFault/OutFault components named {action}. The property is of type xs:anyURI. The property value is either explicitly specified, as described in section 4.4.1 Explicit Association, or the default value computed following the rules from section 4.4.2 Default Action Pattern for WSDL 2.0.

4.4.4 Default Action Pattern for WSDL 1.1

A default pattern is also defined for backwards compatibility with WSDL 1.1. In the absence of an explicitly specified value for the [action] property (see section 4.4.1 Explicit Association), the following pattern is used to construct a default action for inputs and outputs. The general form of an action IRI is as follows:

Example 4-6. Structure of defaulted wsa:Action IRI.

[target namespace][delimiter][port type name][delimiter][input|output name]

For fault messages, the general form of an action IRI is as follows:

Example 4-7. Structure of default wsa:Action IRI for faults

[target namespace][delimiter][port type name][delimiter][operation name][delimiter]Fault[delimiter][fault name]

Where:

[delimiter]

is ":" when the [target namespace] is a URN, otherwise "/". Note that for IRI schemes other than URNs which aren't path-based (i.e. those that outlaw the "/" character), the default action value might not conform to the rules of the IRI scheme. Authors are advised to specify explicit values in the WSDL in this case.

"Fault"

is a literal character string to be included in the action.

[target namespace]

is the target namespace (/definition/@targetNamespace). If [target namespace] ends with a "/" an additional "/" is not added.

[port type name]

is the name of the port type (/definition/portType/@name).

[operation name]

is the {name} of the operation.

[input|output name]

is the name of the element as defined in Section 2.4.5 of WSDL 1.1.

[fault name]

is the name of the fault (/definition/porttype/operation/fault/@name).

For example consider the following WSDL excerpt:

Example 4-8. Example WSDL without explicit wsa:Action values with explicit message names.

<definitions targetNamespace="http://greath.example.com/2004/wsdl/resSvc" ...>
  ...
  <portType name="reservationInterface">
    <operation name="opCheckAvailability">
      <input message="tns:checkAvailability" name="CheckAvailability"/>
      <output message="tns:checkAvailabilityResponse" name="Availability"/>
          <fault message="tns:InvalidDate" name="InvalidDate"/>
    </operation>
  </portType>
  ...
</definitions>
      

[targetNamespace] = http://greath.example.com/2004/wsdl/resSvc

[port type name] = reservationInterface

[input name] = CheckAvailability

[output name] = CheckAvailabilityResponse

[fault name] = InvalidDate

Applying the pattern above with these values we have:

input action = http://greath.example.com/2004/wsdl/resSvc/reservationInterface/CheckAvailability

output action = http://greath.example.com/2004/wsdl/resSvc/reservationInterface/Availability

fault action = http://greath.example.com/2004/wsdl/resSvc/reservationInterface/opCheckAvailability/Fault/InvalidDate

WSDL defines rules for a default input or output name if the name attribute is not present. Consider the following example:

Example 4-9. Example WSDL without explicit wsa:Action values or explicit message names.

<definitions targetNamespace="http://greath.example.com/2004/wsdl/resSvc" ...>
  ...
  <portType name="reservationInterface">
    <operation name="opCheckAvailability">
      <input message="tns:checkAvailability"/>
      <output message="tns:checkAvailabilityResponse"/>
    </operation>
  </portType>
  ...
</definitions>
      

[targetNamespace] = http://greath.example.com/2004/wsdl/resSvc

[port type name] = reservationInterface

According to the rules defined in Section 2.4.5 of WSDL 1.1, if the name attribute is absent for the input of a request response operation the default value is the name of the operation with "Request" appended.

[input name] = opCheckAvailabilityRequest

Likewise, the output defaults to the operation name with "Response" appended.

[output name] = opCheckAvailabilityResponse

Applying the pattern above with these values we have:

input action = http://greath.example.com/2004/wsdl/resSvc/reservationInterface/opCheckAvailabilityRequest

output action = http://greath.example.com/2004/wsdl/resSvc/reservationInterface/opCheckAvailabilityResponse

5. WS-Addressing and WSDL Message Exchange Patterns

This section describes which of the core message properties are mandatory for messages in the various MEPs defined by WSDL.

5.1 WSDL 1.1 Message Exchange Patterns

For backwards compatibility, this section describes which of the core message properties are mandatory for messages in the various MEPs defined by WSDL 1.1.

5.1.1 One-way

This is a straightforward one-way message. No responses are expected but related messages could be sent as part of other message exchanges.

Table 5-1. Message addressing properties for one way message.
Property Mandatory Description
[destination] Y Provides the address of the intended receiver of this message
[action] Y Identifies the semantics implied by this message
[source endpoint] N Message origin. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[reply endpoint] N Intended receiver for replies to this message. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[fault endpoint] N Intended receiver for faults related to this message. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[message id] N Unique identifier for this message. Unused in this MEP, but may be included to facilitate longer running message exchanges.
[relationship] N Indicates relationship to a prior message. Unused in this MEP, but could be included to facilitate longer running message exchanges.

5.1.2 Request-Response

This is request-response. A reply is expected hence mandating [reply endpoint] in the request message. The response message might be a fault.

Table 5-2. Message addressing properties for request message.
Property Mandatory Description
[destination] Y Provides the address of the intended receiver of this message
[action] Y Identifies the semantics implied by this message
[source endpoint] N Message origin. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[reply endpoint] Y Intended receiver for the reply to this message.
[fault endpoint] N Intended receiver for faults related to this message. May be included to direct fault messages to a different endpoint than [reply endpoint].
[message id] Y Unique identifier for this message. Used in the [relationship] property of the reply message.
[relationship] N Indicates relationship to a prior message. Unused in this MEP, but could be included to facilitate longer running message exchanges.

Table 5-3. Message addressing properties for response message.
Property Mandatory Description
[destination] Y Provides the address of the intended receiver of this message
[action] Y Identifies the semantics implied by this message
[source endpoint] N Message origin. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[reply endpoint] N Intended receiver for replies to this message. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[fault endpoint] N Intended receiver for faults related to this message. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[message id] N Unique identifier for this message. Unused in this MEP, but may be included to facilitate longer running message exchanges.
[relationship] Y Indicates that this message is a reply to the request message using the request message [message id] value and the predefined http://www.w3.org/2005/08/addressing/reply IRI.

5.1.3 Notification

From the WS-Addressing perspective this MEP is the same as One-way. The properties defined in 5.1.1 One-way apply to this MEP also.

5.1.4 Solicit-response

From the WS-Addressing perspective this MEP is the same as Request-response. The properties defined in 5.1.2 Request-Response apply to this MEP also.

5.2 WSDL 2.0 Message Exchange Patterns

This section describes which of the core message properties are mandatory for messages in the various MEPs defined by WSDL 2.0 [WSDL 2.0 Adjuncts].

5.2.1 In-only

This is a straightforward one-way message. No responses are expected but related messages could be sent as part of other message exchanges.

Table 5-4. Message addressing properties for in message.
Property Mandatory Description
[destination] Y Provides the address of the intended receiver of this message
[action] Y Identifies the semantics implied by this message
[source endpoint] N Message origin. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[reply endpoint] N Intended receiver for replies to this message. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[fault endpoint] N Intended receiver for faults related to this message. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[message id] N Unique identifier for this message. Unused in this MEP, but may be included to facilitate longer running message exchanges.
[relationship] N Indicates relationship to a prior message. Unused in this MEP, but could be included to facilitate longer running message exchanges.

5.2.2 Robust In-only

This one-way MEP allows fault messages. The [message id] property is needed in the initial message in order to be able to correlate any fault with that message.

Table 5-5. Message addressing properties for in message.
Property Mandatory Description
[destination] Y Provides the address of the intended receiver of this message
[action] Y Identifies the semantics implied by this message
[source endpoint] N Message origin. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[reply endpoint] N* Intended receiver for replies to this message. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[fault endpoint] N* Intended receiver for faults related to this message.
[message id] Y Unique identifier for this message. Used in the [relationship] property of any resulting fault message.
[relationship] N Indicates relationship to a prior message. Unused in this MEP, but could be included to facilitate longer running message exchanges.

* Note that at least one of [fault endpoint] or [reply endpoint] is required for this MEP, so that a fault can be sent if necessary.

Table 5-6. Message addressing properties for fault message.
Property Mandatory Description
[destination] Y Provides the address of the intended receiver of this message
[action] Y Identifies the semantics implied by this message
[source endpoint] N Message origin. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[reply endpoint] N Intended receiver for replies to this message. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[fault endpoint] N Intended receiver for faults related to this message. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[message id] N Unique identifier for this message. Unused in this MEP, but may be included to facilitate longer running message exchanges.
[relationship] Y Indicates that this message is a response to the in message using the in message [message id] value and the predefined http://www.w3.org/2005/08/addressing/reply IRI.

5.2.3 In-out

This is a two-way MEP. A reply is expected hence mandating [reply endpoint] in the request message. The response message might be a fault.

Table 5-7. Message addressing properties for in message.
Property Mandatory Description
[destination] Y Provides the address of the intended receiver of this message
[action] Y Identifies the semantics implied by this message
[source endpoint] N Message origin. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[reply endpoint] Y Intended receiver for the reply to this message.
[fault endpoint] N Intended receiver for faults related to this message. May be included to direct fault messages to a different endpoint than [reply endpoint].
[message id] Y Unique identifier for this message. Used in the [relationship] property of the out message.
[relationship] N Indicates relationship to a prior message. Unused in this MEP, but could be included to facilitate longer running message exchanges.

Table 5-8. Message addressing properties for out message.
Property Mandatory Description
[destination] Y Provides the address of the intended receiver of this message
[action] Y Identifies the semantics implied by this message
[source endpoint] N Message origin. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[reply endpoint] N Intended receiver for replies to this message. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[fault endpoint] N Intended receiver for faults related to this message. Unused in this MEP, but could be included to facilitate longer running message exchanges.
[message id] N Unique identifier for this message. Unused in this MEP, but may be included to facilitate longer running message exchanges.
[relationship] Y Indicates that this message is a response to the in message using the in message [message id] value and the predefined http://www.w3.org/2005/08/addressing/reply IRI.

5.2.4 In-optional-out

This MEP differs from the In-out MEP in that the subsequent message is optional. This difference doesn't affect the message properties so the properties defined in 5.2.3 In-out apply to this MEP also

5.2.5 Out-only

From the WS-Addressing perspective this MEP is the same as In-only. The properties defined in 5.2.1 In-only apply to this MEP also.

5.2.6 Robust Out-only

From the WS-Addressing perspective this MEP is the same as Robust In-only. The properties defined in 5.2.2 Robust In-only apply to this MEP also.

5.2.7 Out-in

From the WS-Addressing perspective this MEP is the same as In-out. The properties defined in 5.2.3 In-out apply to this MEP also.

5.2.8 Out-optional-in

This MEP differs from the Out-in MEP in that the subsequent message is optional. This difference doesn't affect the message properties so the properties defined in 5.2.3 In-out apply to this MEP also

6. Conformance

An endpoint reference whose wsa:Metadata element has among its children the elements defined in 2.1 Referencing WSDL Metadata from an EPR conforms to this specification if it obeys the structural constraints defined in that section.

A WSDL description conforms to this specification when it incorporates directly or indirectly the 3.1 WS-Policy Assertions marker, and obeys the structural constraints defined in section 3. Indicating Use of WS-Addressing appropriate to that marker, and those defined in section 4.4 Action.

An endpoint conforms to this specification if it has a conformant WSDL description associated with it, and receives and emits messages in accordance with the constraints defined in sections 4. Specifying Message Addressing Properties in WSDL and 5. WS-Addressing and WSDL Message Exchange Patterns.

7. References

7.1 Normative

[IETF RFC 2119]
Key words for use in RFCs to Indicate Requirement Levels, S. Bradner, Author. Internet Engineering Task Force, March 1997. Available at http://www.ietf.org/rfc/rfc2119.txt
[IETF RFC 3987]
M. Duerst, M. Suignard, "Internationalized Resource Identifiers (IRIs)", January 2005. (See http://www.ietf.org/rfc/rfc3987.txt.)
[SOAP 1.1]
Simple Object Access Protocol (SOAP) 1.1, D. Box, D. Ehnebuske, G. Kakivaya, A. Layman, N. Mendelsohn, H Frystyk Nielsen, S. Thatte, D. Winer, Editors. W3C Member Submission, 8 May 2000.
[SOAP 1.2]
SOAP Version 1.2 Part 1: Messaging Framework (Second Edition), M. Gudgin, et al., Editors. World Wide Web Consortium, 24 June 2003, revised 27 April 2007. This version of the "SOAP Version 1.2 Part 1: Messaging Framework" Recommendation is http://www.w3.org/TR/2007/REC-soap12-part1-20070427/. The latest version of "SOAP Version 1.2 Part 1: Messaging Framework" is available at http://www.w3.org/TR/soap12-part1/.
[WS-Addressing Core]
Web Services Addressing 1.0 - Core, M. Gudgin, M. Hadley, and T. Rogers, Editors. World Wide Web Consortium, 9 May 2006. This version of the WS-Addressing Core Recommendation is http://www.w3.org/TR/2006/REC-ws-addr-core-20060509. The latest version of WS-Addressing Core is available at http://www.w3.org/TR/ws-addr-core.
[WS-Addressing SOAP Binding]
Web Services Addressing 1.0 - SOAP Binding, M. Gudgin, M. Hadley, and T. Rogers, Editors. World Wide Web Consortium, 9 May 2006. This version of the WS-Addressing Core Recommendation is http://www.w3.org/TR/2006/REC-ws-addr-soap-20060509. The latest version of WS-Addressing SOAP Binding is available at http://www.w3.org/TR/ws-addr-soap.
[WSDL 1.1]
E. Christensen, et al, Web Services Description Language (WSDL) 1.1, March 2001.
[WSDL 2.0]
Web Services Description Language (WSDL) Version 2.0 Part 1: Core Language, R. Chinnici, J-J. Moreau, A. Ryman, S. Weerawarana, Editors. World Wide Web Consortium, 26 June 2007. This version of the "Web Services Description Language (WSDL) Version 2.0 Part 1: Core Language" Recommendation is available is available at http://www.w3.org/TR/2007/REC-wsdl20-20070626. The latest version of "Web Services Description Language (WSDL) Version 2.0 Part 1: Core Language" is available at http://www.w3.org/TR/wsdl20.
[WSDL 2.0 Adjuncts]
Web Services Description Language (WSDL) Version 2.0 Part 2: Adjuncts, R. Chinnici, H. Haas, A. Lewis, J-J. Moreau, D. Orchard, S. Weerawarana, Editors. World Wide Web Consortium, 26 June 2007. This version of the "Web Services Description Language (WSDL) Version 2.0 Part 2: Adjuncts" Recommendation is available at http://www.w3.org/TR/2007/REC-wsdl20-adjuncts-20070626. The latest version of "Web Services Description Language (WSDL) Version 2.0 Part 2: Adjuncts" is available at http://www.w3.org/TR/wsdl20-adjuncts.
[WS Policy 1.5]
Web Services Policy 1.5 - Framework, Asir S Vedamuthu, et al., Editors. World Wide Web Consortium, 4 September 2007. This version of the WS-Policy Framework is http://www.w3.org/TR/2007/REC-ws-policy-20070904. The latest version of WS Policy Framework is available at http://www.w3.org/TR/ws-policy
[WS Policy 1.5 - Attachment]
Web Services Policy 1.5 - Attachment, Asir S Vedamuthu, et al., Editors. World Wide Web Consortium, 4 September 2007. This version of the WS-Policy Attachment is http://www.w3.org/TR/2007/REC-ws-policy-attach-20070904. The latest version of WS Policy Attachment is available at http://www.w3.org/TR/ws-policy-attach
[XML 1.0]
Extensible Markup Language (XML) 1.0 (Fourth Edition), T. Bray, J. Paoli, C. M. Sperberg-McQueen, and E. Maler, Editors. World Wide Web Consortium, 10 February 1998, revised 16 August 2006. This version of the XML 1.0 Recommendation is http://www.w3.org/TR/2006/REC-xml-20060816. The latest version of XML 1.0 is available at http://www.w3.org/TR/xml.
[XML Namespaces]
Namespaces in XML 1.0 (Second Edition), T. Bray, D. Hollander, A. Layman, and R. Tobin, Editors. World Wide Web Consortium, 14 January 1999, revised 16 August 2006. This version of Namespaces in XML 1.0 Recommendation is http://www.w3.org/TR/2006/REC-xml-names-20060816/. The latest version of Namespaces in XML is available at http://www.w3.org/TR/xml-names.
[XML Information Set]
XML Information Set (Second Edition), J. Cowan and R. Tobin, Editors. World Wide Web Consortium, 24 October 2001, revised 4 February 2004. This version of the XML Information Set Recommendation is http://www.w3.org/TR/2004/REC-xml-infoset-20040204/. The latest version of XML Information Set is available at http://www.w3.org/TR/xml-infoset.
[XML Schema Structures]
XML Schema Part 1: Structures Second Edition, H. Thompson, D. Beech, M. Maloney, and N. Mendelsohn, Editors. World Wide Web Consortium, 2 May 2001, revised 28 October 2004. This version of the XML Schema Part 1 Recommendation is http://www.w3.org/TR/2004/REC-xmlschema-1-20041028. The latest version of XML Schema Part 1 is available at http://www.w3.org/TR/xmlschema-1.
[XML Schema Datatypes]
XML Schema Part 2: Datatypes Second Edition, P. Byron and A. Malhotra, Editors. World Wide Web Consortium, 2 May 2001, revised 28 October 2004. This version of the XML Schema Part 2 Recommendation is http://www.w3.org/TR/2004/REC-xmlschema-2-20041028. The latest version of XML Schema Part 2 is available at http://www.w3.org/TR/xmlschema-2.

7.2 Informative

[WS Policy 1.5 - Primer]
Web Services Policy 1.5 - Primer, Asir S Vedamuthu, et al., Editors. World Wide Web Consortium, 10 August 2007. This version of the WS-Policy Primer is http://www.w3.org/TR/2007/WD-ws-policy-primer-20070810. The latest version of WS Policy Primer is available at http://www.w3.org/TR/ws-policy-primer
[WS-Security]
OASIS, Web Services Security: SOAP Message Security, March 2004.

A. Acknowledgements (Non-Normative)

This document is the work of the W3C Web Service Addressing Working Group.

Members of the Working Group are (at the time of writing, and by alphabetical order): Abbie Barbir (Nortel Networks), Andreas Bjärlestam (ERICSSON), Eran Chinthaka (WSO2), Francisco Curbera (IBM Corporation), Glen Daniels (Sonic Software), Vikas Deolaliker (Sonoa Systems, Inc.), Paul Downey (BT), Jacques Durand (Fujitsu Limited), Robert Freund (Hitachi, Ltd.), Marc Goodner (Microsoft Corporation), David Hull (TIBCO Software, Inc.), Yin-Leng Husband (HP), David Illsley (IBM Corporation), Ram Jeyaraman (Microsoft Corporation), Anish Karmarkar (Oracle Corporation), Paul Knight (Nortel Networks), Philippe Le Hégaret (W3C/MIT), Amelia Lewis (TIBCO Software, Inc.), Bozhong Lin (IONA Technologies, Inc.), Mark Little (JBoss Inc.), Jeganathan Markandu (Nortel Networks), Jeff Mischkinsky (Oracle Corporation), Nilo Mitra (ERICSSON), Eisaku Nishiyama (Hitachi, Ltd.), Ales Novy (Systinet Inc.), David Orchard (BEA Systems, Inc.), Gilbert Pilz (BEA Systems, Inc.), Rama Pulavarthi (Sun Microsystems, Inc.), Alain Regnier (Ricoh Company, Ltd.), Tony Rogers (CA), Tom Rutt (Fujitsu Limited), Davanum Srinivas (WSO2), Jiri Tejkl (Systinet Inc.), Katy Warr (IBM Corporation), Steve Winkler (SAP AG), Ümit Yalçinalp (SAP AG), Prasad Yendluri (webMethods, Inc.).

Previous members of the Working Group were: Lisa Bahler (SAIC - Telcordia Technologies), Rebecca Bergersen (IONA Technologies, Inc.), Vladislav Bezrukov (SAP AG), Dave Chappell (Sonic Software), Ugo Corda (Sun Microsystems, Inc.), Michael Eder (Nokia), Yaron Goland (BEA Systems, Inc.), Martin Gudgin (Microsoft Corporation), Arun Gupta (Sun Microsystems, Inc.), Hugo Haas (W3C), Marc Hadley (Sun Microsystems, Inc), Jonathan Marsh (Microsoft Corporation), Mark Nottingham (BEA Systems, Inc.), Mark Peel (Novell, Inc.), Harris Reynolds (webMethods, Inc.), Rich Salz (IBM Corporation), Davanum Srinivas (Computer Associates), Greg Truty (IBM Corporation), Mike Vernal (Microsoft Corporation), Steve Vinoski (IONA Technologies, Inc.), Pete Wenzel (Sun Microsystems, Inc.).

The people who have contributed to discussions on public-ws-addressing@w3.org are also gratefully acknowledged.

B. Compatibility of [action] with previous versions of WS-Addressing (Non-Normative)

This section describes strategies for choosing [action] values consistent between this specification and the WS-Addressing Member Submission published 10 August 2004 (hereafter called "2004-08"). The wsa200408 namespace prefix below refers to the "http://schemas.xmlsoap.org/ws/2004/08/addressing" namespace defined in the 2004-08 version.

The WS-Addressing 1.0 [action] property, which identifies the semantics implied by a message, is semantically equivalent to the [action] message information header defined in the 2004-08 version. Authors are therefore advised to use the same value for 1.0 [action] and 2004-08 [action].

However, when describing services in WSDL, the namespace of the Action attribute used to associate values with WSDL operations differs in the two versions (wsam:Action versus wsa200408:Action), and the default action pattern in WS-Addressing 1.0 differs in two respects from that in the 2004-08 version: the [delimiter] can be either "/" or ":" in 1.0 while in 2004-08 it is always "/", and the default action pattern for faults is closer to that of other messages instead of a constant URI.

If a default action pattern is desired, this specification recommends the 1.0 default action pattern. The 200408 [action] can be made consistent with the 1.0 default by:

  1. specifying wsa200408:Action explicitly when the targetNamespace is a URN, and

  2. specifying wsa200408:Action explicitly when the message is a fault.

If the targetNamespace is a URN, it is not advisable to use the 2004-08 default action pattern, as it leads to malformed IRIs. If the targetNamespace is not a URN, and the 2004-08 default action pattern is in use, the 1.0 [action] value can be made consistent by:

  1. specifying wsam:Action explicitly when the message is a fault.