Microsoft Corporation has published a new architectural model for the next generation of XML Web services together with four specifications supporting that architecture. This Global XML Web Services Architecture "provides a set of principles and guidelines for advancing the protocols and file formats of today's XML Web services to more complex and sophisticated tasks. The four specifications build on XML Web services technologies such as XML, SOAP, WSDL, and UDDI specifications, extending them for global-class computing. The new specifications adhere to the road map outlined by Microsoft and IBM Corp. at the W3C Web Services Workshop in April 2001 and represent a first step toward a comprehensive Global XML Web Services Architecture. (1) WS-Security outlines how to use the W3C specifications XML Signature and XML Encryption; (2) WS-License, along with WS-Security, outlines how existing digital credentials and their associated trust semantics can be securely associated with SOAP messages; (3) WS-Routing describes how to place message addresses in the SOAP message header and enables SOAP messages to travel serially to multiple destinations along a message path [formerly SOAP-RP]; (4) WS-Referral enables the routing between SOAP nodes on a message path to be dynamically configured. As with previous XML Web services specifications, these four will be available for a review period and then submitted to appropriate standards bodies."

Overview of the Global XML Web Services Architecture specifications:

WS-Routing. WS-Routing is a simple, stateless, SOAP-based protocol for routing SOAP messages in an asynchronous manner over a variety of transports like TCP, UDP, and HTTP. With WS-Routing, the entire message path for a SOAP message (as well as its return path) can be described directly within the SOAP envelope. It supports one-way messaging, two-way messaging such as request/response and peer-to-peer conversations, and long running dialogs. See the WS-Routing specification and XML Schema.

WS-Referral. WS-Referral is a protocol that enables the routing strategies used by SOAP nodes in a message path to be dynamically configured. SOAP itself provides a distributed processing model where SOAP messages can have content destined for specific processing nodes. WS-Routing adds to SOAP the capability of describing the actual message path. WS-Referral provides a mechanism to dynamically configure SOAP nodes in a message path to define how they should handle a SOAP message. It is a configuration protocol that enables SOAP nodes to delegate part or all of their processing responsibility to other SOAP nodes. See the WS-Referral specification and the XML Schema.

WS-Security. WS-Security provides a security language for Web services. WS-Security describes enhancements to SOAP messaging providing three capabilities: credential exchange, message integrity, and message confidentiality. These three mechanisms can be used independently or in combination to accommodate a wide variety of security models and encryption technologies. WS-Security provides a general-purpose mechanism for associating licenses (credentials that are signed assertions, e.g. X.509 certificates or Kerberos tickets) with messages. No specific type of credential is required. Message integrity is provided by leveraging XML Signature and licenses to ensure that messages are transmitted without modifications. Similarly, message confidentiality leverages XML Encrypt and licenses to keep portions of a SOAP message confidential. See the WS-Security specification and XML Schema.

WS-License. WS-License describes a set of commonly used license types (credentials that are signed assertions) and describes how they can be placed within the WS-Security "credentials tag." Specifically, the WS-License specification describes how to encode X.509 certificates, Kerberos tickets and XrML licenses as well as arbitrary binary credentials. WS-License includes extensibility mechanisms that can be used to further describe the characteristics of the licenses that are included with a message. See the WS-License specification and XML Schema.