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If there are any aspects of web services, particularly PROGRAMMING LANGUAGES and operating systems, that you are not as familiar with, say this and then talk about your desire to WORK more with them to expand your knowledge. Also, talk about how you WOULD TAKE advantage of any extra training offered by the company.

If there are any aspects of web services, particularly programming languages and operating systems, that you are not as familiar with, say this and then talk about your desire to work more with them to expand your knowledge. Also, talk about how you would take advantage of any extra training offered by the company.

Since there are many operating SYSTEMS and programming languages involved in web SERVICES, try to talk about how you have improved your knowledge of a few, such as Java, PERL, Unix applications or Windows applications. If you know any of these are more prominently USED in the company you’re applying for, talk about them.

Since there are many operating systems and programming languages involved in web services, try to talk about how you have improved your knowledge of a few, such as Java, Perl, Unix applications or Windows applications. If you know any of these are more prominently used in the company you’re applying for, talk about them.

WEB services is at its CORE software that can be ACCESSED online that USES an XML messaging system, which ENCODES the communications in web services. 

Web services is at its core software that can be accessed online that uses an XML messaging system, which encodes the communications in web services. 

The following are the advantages of web services over COM and DCOM:
• It is simple and easy to use web services and it is implemented on different platforms.
• The web services are loosely coupled and their methods and interfaces can be extended.
• Stat information is not CARRIED by web services so that NUMEROUS requests are PROCESSED simultaneously.

The following are the advantages of web services over COM and DCOM:
• It is simple and easy to use web services and it is implemented on different platforms.
• The web services are loosely coupled and their methods and interfaces can be extended.
• Stat information is not carried by web services so that numerous requests are processed simultaneously.

You can prevent WEB services from illegal access USING following ways:
• Using security based on message and ENCRYPTION.
• Access CONTROLS and authentication can also prevent illegal access.

You can prevent web services from illegal access using following ways:
• Using security based on message and encryption.
• Access controls and authentication can also prevent illegal access.

It is a self-sustained and independent unit of software application that is hosted on internet and specific functionalities are implemented to perform business logic. Multiple functionalities are offered by a web service like computing tax, giving UPDATED news, generating pay SLIPS for employees and broadcasting weather report. Application is allowed to EXCHANGE data or share information using web service with various applications on different hardware and operating systems. Thus, web service carries out work to unit software by swapping data IRRESPECTIVE of programming LANGUAGE, hardware and operating system used in the development process. The data transferred by the XML is in the XML format and for communication purpose it uses SOAP, which is a protocol based on XML. Universal Description, Discover and Integration UDDI and Web Services Description Language (WSDL) are used by the web services to describe themselves.

It is a self-sustained and independent unit of software application that is hosted on internet and specific functionalities are implemented to perform business logic. Multiple functionalities are offered by a web service like computing tax, giving updated news, generating pay slips for employees and broadcasting weather report. Application is allowed to exchange data or share information using web service with various applications on different hardware and operating systems. Thus, web service carries out work to unit software by swapping data irrespective of programming language, hardware and operating system used in the development process. The data transferred by the XML is in the XML format and for communication purpose it uses SOAP, which is a protocol based on XML. Universal Description, Discover and Integration UDDI and Web Services Description Language (WSDL) are used by the web services to describe themselves.

The FOLLOWING types of services are provided to web applications:
• XML schema for the descriptions of business INCLUDES SPECIFICATIONS and SERVICE PUBLISHER on web service.
• Web registry of web services include service, business and binding information for web service.

The following types of services are provided to web applications:
• XML schema for the descriptions of business includes specifications and service publisher on web service.
• Web registry of web services include service, business and binding information for web service.

Windows SERVICES can be installed using Service INSTALLER class which is ALSO called as PROJECT installer class.

Windows services can be installed using Service Installer class which is also called as project installer class.

To CREATE all the WINDOWS service, SERVICEBASE CLASS is parent class.

To create all the windows service, ServiceBase class is parent class.

Yes it is POSSIBLE. A process can be SHARED between WINDOWS services.

Yes it is possible. A process can be shared between windows services.

• WEB SERVICES have poor performance when it is COMPARED with other DISTRIBUTION applications such as CORBA, RMI and DCOM.
• Clearly XML is not considered among design goals either brevity of encoding or parsing efficiency.
• When a request is made to the server by the client and before responding to the request if power had GONE then it results in system crash.

• Web services have poor performance when it is compared with other distribution applications such as CORBA, RMI and DCOM.
• Clearly XML is not considered among design goals either brevity of encoding or parsing efficiency.
• When a request is made to the server by the client and before responding to the request if power had gone then it results in system crash.

The advantages of web services are:

Reusability:
Open standards and protocols are used by the web services. Deploying services is easy as they are not component-based model of an application for development. THUS, it is very easy to reuse components of web service as suitable in other services.

Ability to deploy:
Web services are deployed on the internet and without any independent and mapping issues, any user can use it.

Interoperability:
It is the vital benefit of web services, which works outside private NETWORKS and provide developers to find solutions in an effective way. Interoperability is provided between several software’s which are RUNNING on multiple platforms. Virtually, web services do not depend on platform.

Usability:
Reuse of components and services in an infrastructure is allowed by web services. Business logic of multiple platforms is allowed by web services and it is EXPOSED over web. Thus, provides FACILITY of using web services anywhere for various platforms.

The advantages of web services are:

Reusability:
Open standards and protocols are used by the web services. Deploying services is easy as they are not component-based model of an application for development. Thus, it is very easy to reuse components of web service as suitable in other services.

Ability to deploy:
Web services are deployed on the internet and without any independent and mapping issues, any user can use it.

Interoperability:
It is the vital benefit of web services, which works outside private networks and provide developers to find solutions in an effective way. Interoperability is provided between several software’s which are running on multiple platforms. Virtually, web services do not depend on platform.

Usability:
Reuse of components and services in an infrastructure is allowed by web services. Business logic of multiple platforms is allowed by web services and it is exposed over web. Thus, provides facility of using web services anywhere for various platforms.

The characteristics of web services are:

XML – based:
It is based on XML which is platform independent and effectively runs on all the operating systems and it is LANGUAGE independent.

Loosely coupled:
Loosely coupled is nothing but web service consumers are not ATTACHED directly to the web services. Here, the client and server logic is closely attached to each other.

Coarse-grained:
Coarse-grained facility is provided by it for programs and methods in JAVA.

Supports to Remote Procedure Calls:
Remote procedure calls are supported by web services when the transaction takes place while exchanging documents.

ABILITY to be asynchronous and synchronous:
When the client is interested in executing web services, the facility to bind the client is provided by synchronized. Thus, the service is synchronously used by the client. The client is allowed to invoke web service using asynchronous operations, when the client is interested in executing other functions.

Interoperability:
Without external effort, it offers system to system WORK.

The characteristics of web services are:

XML – based:
It is based on XML which is platform independent and effectively runs on all the operating systems and it is language independent.

Loosely coupled:
Loosely coupled is nothing but web service consumers are not attached directly to the web services. Here, the client and server logic is closely attached to each other.

Coarse-grained:
Coarse-grained facility is provided by it for programs and methods in Java.

Supports to Remote Procedure Calls:
Remote procedure calls are supported by web services when the transaction takes place while exchanging documents.

Ability to be asynchronous and synchronous:
When the client is interested in executing web services, the facility to bind the client is provided by synchronized. Thus, the service is synchronously used by the client. The client is allowed to invoke web service using asynchronous operations, when the client is interested in executing other functions.

Interoperability:
Without external effort, it offers system to system work.

Earlier, a WINDOWS service was known as NT services are the applications which are installed in computers as SYSTEM services. These are the services running in the background with an operating system as windows. The key usage of windows services is to decrease consumption of memory essential for doing backend operations. LET us consider an example to understand perfectly. Suppose you are interested in doing MULTIPLE functions like monitoring you computer or any APPLICATION for performance then the status of an application is checked and several devices are managed like printers. Here, windows services are used to reduce the consumption of memory. Additionally, windows services can run on your systems even if you do not log into the system. Also, these services do not have a user interface.

Earlier, a windows service was known as NT services are the applications which are installed in computers as system services. These are the services running in the background with an operating system as windows. The key usage of windows services is to decrease consumption of memory essential for doing backend operations. Let us consider an example to understand perfectly. Suppose you are interested in doing multiple functions like monitoring you computer or any application for performance then the status of an application is checked and several devices are managed like printers. Here, windows services are used to reduce the consumption of memory. Additionally, windows services can run on your systems even if you do not log into the system. Also, these services do not have a user interface.

The abbreviation of UDDI is universal description, DISCOVERY and integration. It is a directory to store web services information to determine, FIND businesses and publish. The communication of UDDI is possible using CORBA, SOAP and Java RMI protocol. The interfaces of UDDI web services are described by WSDL. UDDI is built in the platform of Microsoft .net. UDDI is an open industry which is an enterprise ENABLING business to find each other and DESCRIBE the WAY they interact on web.

The abbreviation of UDDI is universal description, discovery and integration. It is a directory to store web services information to determine, find businesses and publish. The communication of UDDI is possible using CORBA, SOAP and Java RMI protocol. The interfaces of UDDI web services are described by WSDL. UDDI is built in the platform of Microsoft .net. UDDI is an open industry which is an enterprise enabling business to find each other and describe the way they interact on web.

Web SERVICE is like a component sharing information on the web and makes APPLICATION development easy. The facility to MAKE web method means the functioning you implemented in your service is offered by ASP .net. While gaining access the service, a request is sent to client in XML format and input value is passed to web method as a PARAMETER, the response of the server is ALSO in the XML format. One thing is essential that services are running on the web.

Web service is like a component sharing information on the web and makes application development easy. The facility to make web method means the functioning you implemented in your service is offered by ASP .net. While gaining access the service, a request is sent to client in XML format and input value is passed to web method as a parameter, the response of the server is also in the XML format. One thing is essential that services are running on the web.

The full form of WSDL is WEB Services Description LANGUAGE which represents a layer in the protocol STACK of web service. Data types for all XML messages are contained in WSDL and the information about all XML messages are PROVIDED in it. Address information of locating services is given by WSDL.

The full form of WSDL is Web Services Description Language which represents a layer in the protocol stack of web service. Data types for all XML messages are contained in WSDL and the information about all XML messages are provided in it. Address information of locating services is given by WSDL.

The abbreviation of SOAP is Simple Object Access Protocol, which is protocol exchanging information between COMPUTERS. COMPLETE TRANSACTION depends on XML, which is also a platform independent. It is a different way of MESSAGING a system and communicates using TRANSPORT protocol.

The abbreviation of SOAP is Simple Object Access Protocol, which is protocol exchanging information between computers. Complete transaction depends on XML, which is also a platform independent. It is a different way of messaging a system and communicates using transport protocol.

Web service is LIKE SOFTWARE which makes it available on the web. The consistent XML messaging system is used by web services. To use a web service, a message is INVOKED by the CLIENT, and a REQUEST is sent to the server in XML format and a response is given to the client in XML file format by the server. Web services are not dependent on the platform and any application can access it which is developed in any programming language.

Web service is like software which makes it available on the web. The consistent XML messaging system is used by web services. To use a web service, a message is invoked by the client, and a request is sent to the server in XML format and a response is given to the client in XML file format by the server. Web services are not dependent on the platform and any application can access it which is developed in any programming language.

Attaching the WebMethod attribute to a Public method indicates that you want the method exposed as part of the XML Web service. The WebMethod attribute tells .NET that a particular public method should be exposed as a web-callable method. The WebMethod attribute has SIX associated properties to DOCUMENT and change the BEHAVIOR of your web method. They are:

• Description
• MessageName
• EnableSession
• CacheDuration
• TransactionOption
• BufferResponse

The FIRST two properties are used to document a web method, while the others affect its behavior.

Attaching the WebMethod attribute to a Public method indicates that you want the method exposed as part of the XML Web service. The WebMethod attribute tells .NET that a particular public method should be exposed as a web-callable method. The WebMethod attribute has six associated properties to document and change the behavior of your web method. They are:

The first two properties are used to document a web method, while the others affect its behavior.

XML-RPC is a protocol that uses XML messages to perform Remote Procedure Calls. Requests are encoded in XML and sent via HTTP POST; XML responses are EMBEDDED in the body of the HTTP response. More SUCCINCTLY, XML-RPC = HTTP + XML + Remote Procedure Calls. Because XML-RPC is platform independent, diverse applications can communicate with one another. For example, a Java client can speak XML-RPC to a Perl server.

To get a quick sense of XML-RPC, here is a sample XML-RPC request to a weather service (with the HTTP Headers omitted):
<?xml version="1.0" encoding="ISO-8859-1"?>
<methodCall>
<methodName>weather.getWeather</methodName>
<params>
<param><value>10016</value></param>
</params>
</methodCall>
The request consists of a simple element, which specifies the METHOD name (getWeather) and any method parameters (zip code).

XML-RPC is a protocol that uses XML messages to perform Remote Procedure Calls. Requests are encoded in XML and sent via HTTP POST; XML responses are embedded in the body of the HTTP response. More succinctly, XML-RPC = HTTP + XML + Remote Procedure Calls. Because XML-RPC is platform independent, diverse applications can communicate with one another. For example, a Java client can speak XML-RPC to a Perl server.

To get a quick sense of XML-RPC, here is a sample XML-RPC request to a weather service (with the HTTP Headers omitted):
<?xml version="1.0" encoding="ISO-8859-1"?>
<methodCall>
<methodName>weather.getWeather</methodName>
<params>
<param><value>10016</value></param>
</params>
</methodCall>
The request consists of a simple element, which specifies the method name (getWeather) and any method parameters (zip code).

The easiest way to get started with Web services is to learn XML-RPC. Check out the XML-RPC SPECIFICATION or read my book, Web Services Essentials. O'Reilly has also RECENTLY released a book on Programming Web Services with XML-RPC by Simon St.Laurent, Joe Johnston, and Edd Dumbill.

Once you have learned the basics of XML-RPC, move onto SOAP, WSDL, and UDDI. These topics are also covered in Web Services Essentials. For a comprehensive TREATMENT of SOAP, check out O'Reilly's Programming Web Services with SOAP, by Doug Tidwell, James Snell, and Pavel Kulchenko.

The easiest way to get started with Web services is to learn XML-RPC. Check out the XML-RPC specification or read my book, Web Services Essentials. O'Reilly has also recently released a book on Programming Web Services with XML-RPC by Simon St.Laurent, Joe Johnston, and Edd Dumbill.

Once you have learned the basics of XML-RPC, move onto SOAP, WSDL, and UDDI. These topics are also covered in Web Services Essentials. For a comprehensive treatment of SOAP, check out O'Reilly's Programming Web Services with SOAP, by Doug Tidwell, James Snell, and Pavel Kulchenko.

A Web service is a class that allows its METHODS to be called by methods on other machines via common data FORMATS and protocols, such as XML and HTTP. In .NET, the over-the-network method CALLS are commonly implemented through the Simple Object Access Protocol (SOAP), an XML-based protocol describing how to mark up REQUESTS and responses so that they can be TRANSFERRED via protocols such as HTTP. Using SOAP, applications represent and transmit data in a standardized XML-based format.

A Web service is a class that allows its methods to be called by methods on other machines via common data formats and protocols, such as XML and HTTP. In .NET, the over-the-network method calls are commonly implemented through the Simple Object Access Protocol (SOAP), an XML-based protocol describing how to mark up requests and responses so that they can be transferred via protocols such as HTTP. Using SOAP, applications represent and transmit data in a standardized XML-based format.

It is POSSIBLE to process user-defined types (also known as custom types) in a Web service. These types can be passed to or RETURNED from Web methods. Web service CLIENTS also can USE these user-defined types, because the proxy class created for the client contains these type definitions.

Custom types that are sent to or from a Web service are serialized, enabling them to be passed in XML format. This process is referred to as XML SERIALIZATION.

It is possible to process user-defined types (also known as custom types) in a Web service. These types can be passed to or returned from Web methods. Web service clients also can use these user-defined types, because the proxy class created for the client contains these type definitions.

Custom types that are sent to or from a Web service are serialized, enabling them to be passed in XML format. This process is referred to as XML serialization.

The Simple Object Access Protocol (SOAP) is a platform-independent protocol that uses XML to make REMOTE procedure CALLS.

Each request and response is packaged in a SOAP message containing the INFORMATION that a Web service requires to process the message.

SOAP supports an extensive set of types LIKE the PRIMITIVE types, DataSet, DateTime, XmlNode and others. SOAP can also transmit arrays of these types and objects of user-defined types.

The Simple Object Access Protocol (SOAP) is a platform-independent protocol that uses XML to make remote procedure calls.

Each request and response is packaged in a SOAP message containing the information that a Web service requires to process the message.

SOAP supports an extensive set of types like the primitive types, DataSet, DateTime, XmlNode and others. SOAP can also transmit arrays of these types and objects of user-defined types.

PEOPLE have been using Remote PROCEDURE Calls (RPC) for some time now, and they long ago discovered how to send such calls over HTTP.
So, what is really new about Web services? The answer is XML.
XML lies at the core of Web services, and provides a common language for describing Remote Procedure Calls, Web services, and Web service directories.
Prior to XML, one COULD share data among different applications, but XML makes this so much easier to do. In the same vein, one can share services and CODE without Web services, but XML makes it easier to do these as WELL.
By standardizing on XML, different applications can more easily talk to one another, and this makes software a whole lot more interesting.

People have been using Remote Procedure Calls (RPC) for some time now, and they long ago discovered how to send such calls over HTTP.
So, what is really new about Web services? The answer is XML.
XML lies at the core of Web services, and provides a common language for describing Remote Procedure Calls, Web services, and Web service directories.
Prior to XML, one could share data among different applications, but XML makes this so much easier to do. In the same vein, one can share services and code without Web services, but XML makes it easier to do these as well.
By standardizing on XML, different applications can more easily talk to one another, and this makes software a whole lot more interesting.

The World Wide Web Consortium (W3C) is actively PURSUING standardization of Web service protocols. In SEPTEMBER 2000, the W3C established an XML Protocol Activity. The goal of the GROUP is to establish a formal standard for SOAP. A draft version of SOAP 1.2 is CURRENTLY under review, and progressing through the official W3C recommendation process.
On January 25, 2002, the W3C also announced the formation of a Web Service Activity. This new activity will include the current SOAP work as well as two new groups. The first new group is the Web Services Description Working Group, which will take up work on WSDL. The second new group is the Web Services ARCHITECTURE Working Group, which will attempt to create a cohesive framework for Web service protocols.

The World Wide Web Consortium (W3C) is actively pursuing standardization of Web service protocols. In September 2000, the W3C established an XML Protocol Activity. The goal of the group is to establish a formal standard for SOAP. A draft version of SOAP 1.2 is currently under review, and progressing through the official W3C recommendation process.
On January 25, 2002, the W3C also announced the formation of a Web Service Activity. This new activity will include the current SOAP work as well as two new groups. The first new group is the Web Services Description Working Group, which will take up work on WSDL. The second new group is the Web Services Architecture Working Group, which will attempt to create a cohesive framework for Web service protocols.

Windows service is a application that RUNS in the background. It is equivalent to a NT service. The EXECUTABLE created is not a Windows application, and hence you can’t just click and run it . it needs to be INSTALLED as a service, VB.Net has a facility where we can add an installer to our program and then USE a utility to install the service. Whereas this is not the case with standard EXE.

Windows service is a application that runs in the background. It is equivalent to a NT service. The executable created is not a Windows application, and hence you can’t just click and run it . it needs to be installed as a service, VB.Net has a facility where we can add an installer to our program and then use a utility to install the service. Whereas this is not the case with standard exe.

Windows SERVICE cannot be installed on Win9x machines even though the .NET FRAMEWORK RUNS on machine.

Windows service cannot be installed on Win9x machines even though the .NET framework runs on machine.

No.

No.

Just CALL SetNoStore on the HttpCachePolicy object exposed through the RESPONSE object’s Cache property, as demonstrated here:

&LT;%@ Page Language=”C#” %>

<%
Response.Cache.SetNoStore ();
Response.Write (DateTime.Now.ToLongTimeString ());
%>

SetNoStore works by returning a Cache-Control: private, no-store HEADER in the HTTP response. In this EXAMPLE, it prevents caching of a Web page that shows the current time.

Just call SetNoStore on the HttpCachePolicy object exposed through the Response object’s Cache property, as demonstrated here:

<%@ Page Language=”C#” %>

<%
Response.Cache.SetNoStore ();
Response.Write (DateTime.Now.ToLongTimeString ());
%>

SetNoStore works by returning a Cache-Control: private, no-store header in the HTTP response. In this example, it prevents caching of a Web page that shows the current time.

ASP.NET maps the FILE name extension VSDISCO to an HTTP handler that scans the host directory and subdirectories for ASMX and DISCO files and returns a dynamically generated DISCO document. A client who requests a VSDISCO file GETS BACK what appears to be a static DISCO document.

ASP.NET maps the file name extension VSDISCO to an HTTP handler that scans the host directory and subdirectories for ASMX and DISCO files and returns a dynamically generated DISCO document. A client who requests a VSDISCO file gets back what appears to be a static DISCO document.

VSDISCO files are DISCO files that support dynamic discovery of Web services. If you PLACE the FOLLOWING VSDISCO file in a directory on your Web server, for example, it returns references to all ASMX and DISCO files in the host directory and any subdirectories not NOTED in <EXCLUDE>ELEMENTS:


<DYNAMICDISCOVERY
xmlns=”urn:schemas-dynamicdiscovery:disco.2000-03-17″>
<EXCLUDE path=”_vti_cnf” />
<EXCLUDE path=”_vti_pvt” />
<EXCLUDE path=”_vti_log” />
<EXCLUDE path=”_vti_script” />
<EXCLUDE path=”_vti_txt” />
</DYNAMICDISCOVERY>

VSDISCO files are DISCO files that support dynamic discovery of Web services. If you place the following VSDISCO file in a directory on your Web server, for example, it returns references to all ASMX and DISCO files in the host directory and any subdirectories not noted in <EXCLUDE>elements:


<DYNAMICDISCOVERY
xmlns=”urn:schemas-dynamicdiscovery:disco.2000-03-17″>
<EXCLUDE path=”_vti_cnf” />
<EXCLUDE path=”_vti_pvt” />
<EXCLUDE path=”_vti_log” />
<EXCLUDE path=”_vti_script” />
<EXCLUDE path=”_vti_txt” />
</DYNAMICDISCOVERY>

False.

False.

HTTP with SOAP

HTTP with SOAP

• XML Web services are more restricted than objects exposed over .NET Remoting.
• XML Web services support open standards that target cross-platform use.
• XML Web services are generally EASIER to create and due to the restricted NATURE of XML Web services, the design issues are simplified.
• XML Web services support only SOAP MESSAGE formatting, which uses larger XML text messages.
• Communication with .NET Remoting can be faster than XML Web SERVICE communication with a binary formatter.
• XML Web services are designed for use between companies and organizations.
• XML Web services don't require a dedicated hosting program because they are always hosted by ASP.NET.
• CONSUMERS can use XML Web services just as easily as they can download HTML pages from the Internet. Thus there's no need for an administrator to open additional ports on a firewall as they work through MS-IIS and ASP.NET

• XML Web services are more restricted than objects exposed over .NET Remoting.
• XML Web services support open standards that target cross-platform use.
• XML Web services are generally easier to create and due to the restricted nature of XML Web services, the design issues are simplified.
• XML Web services support only SOAP message formatting, which uses larger XML text messages.
• Communication with .NET Remoting can be faster than XML Web service communication with a binary formatter.
• XML Web services are designed for use between companies and organizations.
• XML Web services don't require a dedicated hosting program because they are always hosted by ASP.NET.
• Consumers can use XML Web services just as easily as they can download HTML pages from the Internet. Thus there's no need for an administrator to open additional ports on a firewall as they work through MS-IIS and ASP.NET

.Net web services are built on XML-based standards for EXCHANGING data. This means .NET web services can support only those data types that can be recognized by the XML schema standard. There are many proprietary .Net objects such as FileSteam, Event log ETC. are not supported in the web services. These data types are .Net specific types that are not universally recognized, i.e. .Net specific only.

You can EVEN exchange custom objects using .Net web services. The only limitation is that only public data members are transmitted, and all public members and properties must use one of the other supported data types.

You can use DataSet and DataTable to return information from database but can't use other ADO.NET objects such as DataColumns and DataRows.

.Net offers a distributed technology called .Net REMOTING that can plays around WIDE range of .Net specific data type. But unfortunately, .Net remoting doesn't support client other than .Net.

.Net web services are built on XML-based standards for exchanging data. This means .NET web services can support only those data types that can be recognized by the XML schema standard. There are many proprietary .Net objects such as FileSteam, Event log etc. are not supported in the web services. These data types are .Net specific types that are not universally recognized, i.e. .Net specific only.

You can even exchange custom objects using .Net web services. The only limitation is that only public data members are transmitted, and all public members and properties must use one of the other supported data types.

You can use DataSet and DataTable to return information from database but can't use other ADO.NET objects such as DataColumns and DataRows.

.Net offers a distributed technology called .Net remoting that can plays around wide range of .Net specific data type. But unfortunately, .Net remoting doesn't support client other than .Net.

DISCO
DISCO, an ABBREVIATION of discovery, is a file that groups TOGETHER a list of related web services. A company that offers web services publishes a DISCO file on its server that has links of all the web services it PROVIDES. The client requests this file to see all the available web services. This standard is useful when client already know about a company that offers web services. You can also use DISCO standard while working in local network. It is not helpful to find all web services over the internet.

UDDI
UDDI (Universal Description, Discovery, and Integration) offers centralized directory for web services over the internet. It hosts web services from different companies and can be used by the clients to find web services of their SPECIFIC need. To make web services shared publicly, they have to be published in UDDI.

DISCO
DISCO, an abbreviation of discovery, is a file that groups together a list of related web services. A company that offers web services publishes a DISCO file on its server that has links of all the web services it provides. The client requests this file to see all the available web services. This standard is useful when client already know about a company that offers web services. You can also use DISCO standard while working in local network. It is not helpful to find all web services over the internet.

UDDI
UDDI (Universal Description, Discovery, and Integration) offers centralized directory for web services over the internet. It hosts web services from different companies and can be used by the clients to find web services of their specific need. To make web services shared publicly, they have to be published in UDDI.

FOLLOWING are the standards used by WEB services:

WSDL
WSDL is used to create interface definition for a web services. It describes all about methods to the client, i.e. methods available in a web service, their parameters and return values.

SOAP
SOAP, Simple Object Access Protocol is a communication protocol, a way to structure data, based on XML. The web services use SOAP message format to encode information before sending.

HTTP
The SOAP message format in web services USES HTTP as communication protocol, i.e. SOAP MESSAGES are sent over HTTP channels.

DISCO
It is used to create discovery documents that provide LINKS to multiple web service endpoints. The DISCO standard creates a single file that groups a list of related web services. A company can publish a DISCO file on its server that contains links to all the web services it provides.

UDDI
A standard for creating business registries that catalog companies, the web services they provide, and the corresponding URLs for their WSDL contracts.

Following are the standards used by web services:

WSDL
WSDL is used to create interface definition for a web services. It describes all about methods to the client, i.e. methods available in a web service, their parameters and return values.

SOAP
SOAP, Simple Object Access Protocol is a communication protocol, a way to structure data, based on XML. The web services use SOAP message format to encode information before sending.

HTTP
The SOAP message format in web services uses HTTP as communication protocol, i.e. SOAP messages are sent over HTTP channels.

DISCO
It is used to create discovery documents that provide links to multiple web service endpoints. The DISCO standard creates a single file that groups a list of related web services. A company can publish a DISCO file on its server that contains links to all the web services it provides.

UDDI
A standard for creating business registries that catalog companies, the web services they provide, and the corresponding URLs for their WSDL contracts.

WEB Services are SUPPORTED on a wide range of platforms.

Web services MAY extend its interface and add new methods without affecting the clients as long as they still provide the old methods and parameters.

• A client makes a request to a web service, the web service returns the result, and the connection is closed. There is no permanent connection. This makes it easy to SCALE up and support many clients at a time.
• Firewalls can pose a challenge for distributed object technologies. The only thing that almost always gets through firewalls is HTTP traffic on ports 80 and 443. Because web services use HTTP, they can pass through firewalls without explicit configuration.

Web Services are supported on a wide range of platforms.

Web services may extend its interface and add new methods without affecting the clients as long as they still provide the old methods and parameters.

• A client makes a request to a web service, the web service returns the result, and the connection is closed. There is no permanent connection. This makes it easy to scale up and support many clients at a time.
• Firewalls can pose a challenge for distributed object technologies. The only thing that almost always gets through firewalls is HTTP traffic on ports 80 and 443. Because web services use HTTP, they can pass through firewalls without explicit configuration.

Web services
Web services use HTTP protocol for sending and receiving messages between the applications.
The data encoding in web services is based on XML.
Web services are DEFINED using WSDL (Web Services DESCRIPTION LANGUAGE).

• Web services are discovered using UDDI (Universal Description, Discovery and Integration).
• Web services are firewalls friendly.
• Web services supports interoperability i.e. cross platform integration is possible.

CORBA and DCOM
• These technologies use non-standard protocol, i.e. CORBA uses IIOP (Inter Internet Object Protocol), and DCOM uses RPC (Remote Procedure Calls)
• CORBA components are defined using CORBA Interface Description Language; DCOM components are defined using Microsoft Interface definition languages
• CORBA components are discovered using the CORBA registry, DCOM using the Registry.
• DCOM is a proprietary protocol that does not support interoperability and has firewall problems as DCOM transfers data in binary FORMAT and it uses many ports to call remote functions.
• CORBA uses the IIOP protocol, which is non-Internet friendly.
• CORBA and DCOM are fine for building enterprise applications that runs on the same platform and not good enough for applications that span platforms and languages.

Web services
Web services use HTTP protocol for sending and receiving messages between the applications.
The data encoding in web services is based on XML.
Web services are defined using WSDL (Web Services Description Language).

• Web services are discovered using UDDI (Universal Description, Discovery and Integration).
• Web services are firewalls friendly.
• Web services supports interoperability i.e. cross platform integration is possible.

CORBA and DCOM
• These technologies use non-standard protocol, i.e. CORBA uses IIOP (Inter Internet Object Protocol), and DCOM uses RPC (Remote Procedure Calls)
• CORBA components are defined using CORBA Interface Description Language; DCOM components are defined using Microsoft Interface definition languages
• CORBA components are discovered using the CORBA registry, DCOM using the Registry.
• DCOM is a proprietary protocol that does not support interoperability and has firewall problems as DCOM transfers data in binary format and it uses many ports to call remote functions.
• CORBA uses the IIOP protocol, which is non-Internet friendly.
• CORBA and DCOM are fine for building enterprise applications that runs on the same platform and not good enough for applications that span platforms and languages.

• The key benefit of having distributed COMPONENTS is that they spread out the load over different machines.
• The components can be upgraded WITHOUT disturbing the clients CODE.
• The distributed application IMPROVES security. For EXAMPLE, a company who has many agents wouldn’t like those agents to have direct access to its database. Instead, these agents can be granted access to the components running on the corporate server which can be controlled and restricted.

• The key benefit of having distributed components is that they spread out the load over different machines.
• The components can be upgraded without disturbing the clients code.
• The distributed application improves security. For example, a company who has many agents wouldn’t like those agents to have direct access to its database. Instead, these agents can be granted access to the components running on the corporate server which can be controlled and restricted.

The need of distributed technologies arises with the REQUIREMENT of distributed computing applications. The distributed computing allows partitioning of application logic into UNITS and SPREADING the unit over different computers of a network or across different networks. This helps in spreading out loads over many computers. The components once developed can be reuse by other applications. There are many technologies developed to allow the DISTRIBUTION and reuse of application logic.

The need of distributed technologies arises with the requirement of distributed computing applications. The distributed computing allows partitioning of application logic into units and spreading the unit over different computers of a network or across different networks. This helps in spreading out loads over many computers. The components once developed can be reuse by other applications. There are many technologies developed to allow the distribution and reuse of application logic.

DEPLOYING the .Net Web Services is as SIMPLE as any ASP.NET application. Similar to ASP.NET applications, you need to COPY or UPLOAD the .ASMX file and the .DISCO files to the appropriate directories, and that's it.

Deploying the .Net Web Services is as simple as any ASP.NET application. Similar to ASP.NET applications, you need to copy or upload the .ASMX file and the .DISCO files to the appropriate directories, and that's it.

We have a NUMBER of heterogeneous technologies available on INTERNET. The demand for REUSABLE components across platforms and programming languages are high. Most of the components have the limitation that they can't share or exchange data across different platforms, they are mostly language specific or platform specific. The technologies like COM, RMI, CORBA etc. contributed best to fulfill REQUIREMENTS to some extent, but components result from these said technologies are mostly either language specific or platform specific.
To avoid above problem, we NEED to have web services. Through web services we have overcome the problem of interoperability between languages and platforms. Web services uses SOAP as transport protocol which uses a text based messaging model, i.e. XML to communicate between disparate systems.

We have a number of heterogeneous technologies available on internet. The demand for reusable components across platforms and programming languages are high. Most of the components have the limitation that they can't share or exchange data across different platforms, they are mostly language specific or platform specific. The technologies like COM, RMI, CORBA etc. contributed best to fulfill requirements to some extent, but components result from these said technologies are mostly either language specific or platform specific.
To avoid above problem, we need to have web services. Through web services we have overcome the problem of interoperability between languages and platforms. Web services uses SOAP as transport protocol which uses a text based messaging model, i.e. XML to communicate between disparate systems.

ASP.NET web services are the great way to expose your middle tier components via internet. These components offer no issue communicating across firewalls as they use SOAP as transport protocols that TRANSMIT structured data using HTTP channel. Thus, message can be easily EXCHANGED through port 80, i.e. through internet data port without being getting hampered by corporate firewalls or proxy server.

Web services can fit in the situation when we require integrating disparate systems WRITTEN by separate vendors via internet.
Web services are primarily being used for B2B integration like authorizing employees, supplier, electronically signing of invoice ETC.

ASP.NET web services are the great way to expose your middle tier components via internet. These components offer no issue communicating across firewalls as they use SOAP as transport protocols that transmit structured data using HTTP channel. Thus, message can be easily exchanged through port 80, i.e. through internet data port without being getting hampered by corporate firewalls or proxy server.

Web services can fit in the situation when we require integrating disparate systems written by separate vendors via internet.
Web services are primarily being used for B2B integration like authorizing employees, supplier, electronically signing of invoice etc.

In .Net, a web service is bind with three different protocols such as HTTP/POST, HTTP/GET, and SOAP. This allows client with three options to choose for communication. The protocols are included in the WSDL file that is automatically generated in .NET.

Http-Get and Http-Post can only be USED when name/value pairs of data is dealt with. But when data is complex in nature such as ASP.NET DATASET, XML notes etc, then we can use SOAP that serializes data in simpler form before SENDING.

In .Net, a web service is bind with three different protocols such as HTTP/POST, HTTP/GET, and SOAP. This allows client with three options to choose for communication. The protocols are included in the WSDL file that is automatically generated in .NET.

Http-Get and Http-Post can only be used when name/value pairs of data is dealt with. But when data is complex in nature such as ASP.NET dataset, XML notes etc, then we can use SOAP that serializes data in simpler form before sending.

• Web service is the way to publish application's function on web that can be accessible to the rest of the world.
• Web services are the components that can be used by other applications
• ASP.NET offers easy way to develop web services, just precede the functions with a special WebMethod ()> attribute in order them to work as Web Service.
• Web services are discovered using UDDI DIRECTORY services.
• Web services are built on XML standard and use SOAP protocol that allows them to communicate across different platforms and programming languages.
• Web services easily manage to work across corporate firewalls as they use HTTP protocol which is firewall friendly.
• Web services platform elements are
SOAP (Simple Object Access Protocol)
UDDI (Universal Description, Discovery and Integration)
WSDL (Web Services Description Language)
• The web services are built on internet standards that are not platform or language SPECIFIC.
• The .Net framework provides in-built classes to build and consume web services.
• The components offered by web services are reusable.
• The examples of web service components can be shipment tracking, translation utility, weather FORECASTING, sports SCORES etc.

• Web service is the way to publish application's function on web that can be accessible to the rest of the world.
• Web services are the components that can be used by other applications
• ASP.NET offers easy way to develop web services, just precede the functions with a special WebMethod ()> attribute in order them to work as Web Service.
• Web services are discovered using UDDI directory services.
• Web services are built on XML standard and use SOAP protocol that allows them to communicate across different platforms and programming languages.
• Web services easily manage to work across corporate firewalls as they use HTTP protocol which is firewall friendly.
• Web services platform elements are
SOAP (Simple Object Access Protocol)
UDDI (Universal Description, Discovery and Integration)
WSDL (Web Services Description Language)
• The web services are built on internet standards that are not platform or language specific.
• The .Net framework provides in-built classes to build and consume web services.
• The components offered by web services are reusable.
• The examples of web service components can be shipment tracking, translation utility, weather forecasting, sports scores etc.

Following are the STEPS to GET a proxy object of a web service at the client side.

• Access UDDI NODE for a list of web services.
• Services thus responded by UDDI have URL pointing to DISCO or WSDL DOCUMENT.
• Parse DISCO and WSDL document and build a proxy object which can communicate with the web service.

Following are the steps to get a proxy object of a web service at the client side.

UDDI, Universal description, discovery and integration:
It is the directory that is USED to publish and discover public web services.

DISCO, Discovery:
commonly known as Discovery. Discovery clubs together COMMON services and exposes schema document of the web services.

WSDL, Web Service description LANGUAGE:
This is used to describe web services. The description includes

• URL of web services
• Method and properties supported by web services
• Data type it SUPPORTS.
• Protocol detail it supports.

UDDI, Universal description, discovery and integration:
It is the directory that is used to publish and discover public web services.

DISCO, Discovery:
commonly known as Discovery. Discovery clubs together common services and exposes schema document of the web services.

WSDL, Web Service description language:
This is used to describe web services. The description includes