Simple Object Access Protocol (SOAP) Mark H Needleman Data Research Associates, Inc. ZIG Meeting December 2000

Background n Developed by IBM, Microsoft, Lotus, and others n Submitted to W3C - Became W3C Note in May 1998 n Current Version is 1.1 See: n n Input Document to New W3C XML Protocol Working Group

Design Goals n Simplicity n Extensibility n Not Exclusive to HTTP - HTTP Binding defined in Specification n Need to expose more of what is being run on top of HTTP to help Fireall Administrators do better filtering

SOAP Design n Lightweight Information Exchange in a Decentralized Environment n XML Based n Envelope/Body Framework for defining whats in a message and how to process it n Encoding Rules n Convention for expressing RPC calls and responses

Sample Soap Message POST /StockQuote HTTP/1.1 Host: Content-Type: text/xml; charset="utf-8" Content-Length: nnnn SOAPAction: "Some-URI" DIS

SOAP Message Embedded in HTTP Response HTTP/ OK Content-Type: text/xml; charset="utf-8" Content-Length: nnnn 34.5

SOAP Messaging Models n Request/Response n One way n Multicast

Why NCIP Did Not Use SOAP n Not an “Official Standard” n Uncertainty about support n Lack of Deployment n Some Ignorance about SOAP Itself n Didn’t want to add one more level of complexity into the mix n No good sense of what it would do for us or what problems it might solve

W3C XML Protocol WG n Developing an Envelope for encapsulating XML - must support distributed extensibility, evolvability, and intermediaries n A convention for the content of the envelope when used for RPC n A mechanism for serializing data n A convention for the use of HTTP

XML Protocol WG (2) n Currently defining requirements - expect to publish initial draft soon n Will be coordinating with other activities like IETF work n Doing much of its work publicly - discussions happen on public mailing list n