Home > Articles

SOAP and Web services

The Simple Object Access Protocol (SOAP) and Web services play a major role in the Microsoft .NET Enterprise Solutions platform. A Web Service is a piece of application code made available over the Web via standard Internet protocols such as HTTP and TCP/IP. SOAP is a lightweight protocol that travels on top of HTTP. It provides the information transport layer for application communication via Web services. Software engineers developing solutions that target the Microsoft .NET Enterprise Solutions Platform build applications that exchange data between various Web services to produce a single, cohesive distributed software application.

Simplicity is the fundamental principle behind the development of SOAP. SOAP does not introduce new technological innovations, but instead builds upon reliable, well known Internet standards like XML and HTTP. As a result, software engineers can leverage existing knowledge of the Internet to develop SOAP-based Web services targeting the Microsoft .NET Enterprise Solutions Platform.

That said, we can formulate three important points about what SOAP is:

  • SOAP is formatted using XML and transported through HTTP requests. A client sends a SOAP message to a server via HTTP and the server performs application logic based on the client request.

  • SOAP needs HTTP, nothing else. SOAP is not concerned with operating systems, development languages, or application object models.

  • SOAP works with existing firewalls, routers, and proxy servers. A network administrator does not have to go out and buy new hardware to support SOAP-based software systems.

Now that we have covered what SOAP is, we will discuss the two distinct types of SOAP messages:

  1. Clients send SOAP messages to a server using a Call message.

  2. Servers respond back using a Response message.

Listing 3.3 illustrates a SOAP Call message.

Listing 3.3  SOAP Call Message

POST /RegisterPets HTTP/1.1
Host: www.gasullivan.com
Content-Type: text/xml
Content-Length: xxxx
SOAPMethodName: http://www.gasullivan.com/PetService

<SOAP:Envelope xmlns:SOAP="urn:schemas-xmlsoap-org:soap.v1">
            <XML Payload Goes Here!>

The first four lines in Listing 3.3 are common HTTP syntax. POST is the request type. Hostname, Content-Type, and Content-Length are required for all HTTP messages. Notice the Content-Type of text/xml. XML keeps popping up everywhere! The text/xml value indicates that the payload of this HTTP request is XML. In fact, the SOAP message is a well-formed XML document comprised of a required <SOAP:Envelope> element, a required <SOAP:Body> element, and an optional <SOAP:Header> element. The <SOAP:Header> is not shown in the listing, but would exist between the Envelope and Body elements. A server receiving this message sees the SOAPMethodName in the HTTP Header and executes an AddPetsToRegistry procedure call to add our household pets to a fictitious pet repository at G.A. Sullivan.

Listing 3.4 shows a response to the SOAP Call message above.

Listing 3.4  SOAP Response Message

HTTP/1.1 200 OK
Content-Type: text/xml
Content-Length: xxxx

<SOAP:Envelope xmlns:SOAP=" urn:schemas-xmlsoap-org:soap.v1"
            <return><XML Payload Goes Here!><return>

Here we see a typical HTTP 1.1 response with an XML document as the response body. The top three lines are similar to the SOAP Call request. The first line is the HTTP response code and the second and third lines describe content type and length. Again we see the XML based SOAP message with the <AddPetsToRegistryResponse> element containing a <return> element. The actual payload of the response would be an XML document traveling as a child of the <return> element.


A Web Service accepts messages from a client, performs work based on information contained in the message, and sends a response back to the client. How does a client, or Web Service consumer, learn about the methods a Web Service exposes? This process is enabled through WSDL, the Web Service Description Language. This section explains WSDL and how it fits into the Web services picture.

WSDL is an XML specification that developers use to detail which methods, parameters, and protocols a Web Service exposes. WSDL can be loosely compared to a text-based COM type library that is not specific to any particular operating system platform. It acts as a contract between a Web Service consumer and the Web Service itself.

Imagine a set of cool web services that exist at a site called gasTIX.com. The gasTIX Web services allow customers to search for tickets to upcoming concerts and sporting events. As developers, all we know about is gasTIX.com, not specific endpoints at the site that expose WSDL documents to develop against. The Discovery Protocol (DISCO) defines an XML-based discovery document format, along with a protocol, giving us the ability to scour gasTIX.com for services of interest. The discovery page lists all Web services and the methods available for those services. It also details the expected parameters for each method and a description of the return value.

Taking this one step further, pretend we do not know the specific URL for the Web services we are interested in. The Universal Description, Discovery, and Integration (UDDI) specification allows Web Service authors to advertise the location of their services and gives Web Service consumers the ability to find these services.


For more information on SOAP and Web services, see the following web links:

Microsoft Web services Developer Center: msdn.microsoft.com/webservices/

SOAP Specification Version 1.1: msdn.microsoft.com/xml/general/soapspec.asp

Web services Description Language 1.1: msdn.microsoft.com/xml/general/wsdl.asp

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020