Understanding Windows Azure Connect – PDC10 Session Review

Introducing Windows Azure Connect

• Secure network connectivity between on-premises and cloud
  • Supports standard IP protocols (TCP, UDP)
• Example use cases:
  • Enterprise app migrated to Windows Azure that requires access to on-premise SQL Server
  • Windows Azure app domain-joined to corporate Active Directory
  • Remote administration and troubleshooting of Windows Azure roles
• Simple setup and management

Roadmap

• CTP release by end of 2010
  • Support connect from Azure to non-Azure resources
    • Supports Windows Server 2008 R2, Windows Server 2008, Windows 7, Windows Vista SP1, and up
• Future releases
  • Enable connectivity using existing on-premises VPN devices

Closer Look

• Three steps to setup Windows Azure connect
  1. Enable Windows Azure (WA) roles for External connectivity via service Model
     • Select only the roles that should be enabled for external onnectivity
  2. Enable local computers for connectivity by installing WA Connect Agent
  3. Configure/Manage your network policy that defines which Azure roles and which Azure computers can communicate.
     • defined using the Connect Portal
• After the Configuration/Management of the Network Polity, Azure Connect automatically setups secure IP-level network between connected role instances and local computers
  • Tunnel firewall/NAT/s through hosted relay service
  • Secured via end-to-end IPSec
  • DNS name resolution

Windows Azure Service Deployment

• To use Connect for a Windows Azure Service, enable one or more of its Roles
  • For Web & Worker Roles, include the connect plug-in as part of the Service Model (using .csdef file)
  • For VM Roles, install the connect agent in VHD image using Connect VM Install package
  • Connect agent will automatically be deployed for each new role instance that starts up
• Connect agent configuration is managed through the ServiceConfiguration (.cscfg file)
  • One one configuration setting is required
    • ActivationToken
      • Unique per-subscription token, accessed from Admin UI
  • Several Optional settings for managing AD domain-join and service availability

Deployment

On-Premise

• Local computers are enabled for connectivity by installing & activating the Connect Agent. It can be retrieved from:
  • Web-based installation link
    • Retrieved from the Admin Portal
    • Contains per-subscription activation token embedded in the url
  • Standalone install package
    • Retrieved from the Admin Portal
    • Enabled installation using existing software distribution tools
• Connect agent tray icon & client UI, enables us to:
  • View activation state & connectivity status
  • Refresh network policy
• Connect agent automatically manages network connectivity, by:
  • Setting up a virtual network adapter
  • “Auto-connecting” to Connect relay service as needed
  • Configuring IPSec policy based on network policy
  • Enabling DNS name resolution
  • Automatically syncing latest network policies

Management of Network Policy

• Connect network policy managed through Windows Azure admin portal
  • Managed on a per-subscription basis
• Local Computers are organized into groups
  • Eg. “SQL Server Group”, “Laptops Group”, …
  • A computer can only belong to a single group at a time
  • Newly activated computers aren’t assigned to any group
• Windows Azure roles can be connected to groups
  • Enabled network connectivity between all Role instances (VMs) and local computer in the Group
  • Windows Azure connect doesn’t connect to other Windows Azure Roles
• Groups can be connected to other Groups
  • Enabled network connectivity between computers in each group
  • A group can be ‘interconnected’ – enables connectivity within the group
  • Useful for ad-hoc & roaming scenarios
    • Eg. your laptop having a secure connection back to a server that resides inside the corp net

Network Behavior

• Connect resources (Windows Azure role instances and external machines) have secure IP-level network connectivity
  • Regardless of physical network topology (Firewall / NATs) as long as they support outbound HTTPs access to Connect Relay service
• Each connected machine has a routable IPv6 address
  • Connect agent sets up the virtual network address
  • No changes to existing networks
• Communication between resources is secured via end-to-end certificate-based IPSec
  • Scoped to Connect Virtual network
  • Automated management of IPSec certificates
• DNS name resolution for connected resources based on machine names
  • Both directions are supported (Windows Azure to Local Computer or vice-versa)

Active Directory Domain Join

• Connect plug-in support domain-join of Windows Azure roles to on-premise Active Directory
• Eg. Scenarios:
  • Log into Windows Azure using Domain Accounts
  • Connect to on-premise SQL Server using Windows Integrated Authentication
  • Migrate LOB apps to cloud that assume domain-join environment
• Process:
  1. Install Connect agent on DC/DNS servers
     • Recommendation: create a dedicated site in the case of multiple DC environment
  2. Configure Connect plug-in to automatically join Windows Azure role instances to Active Directory
     • Specify credentials used for domain-join operation
     • Specify the target OU for Windows Azure roles
     • Specify the list of domain users / groups to add to the local administrators group
  3. Configure the network policy to enable connectivity between Windows Azure roles and DC/DNS Servers
  • Note: New Windows Azure role instances will automatically be domain-joined

Finally the recap of Windows Azure Connect

• Enables secure network connectivity between Windows Azure and on-premise resources
• Simple to Setup & Manage
  • Enabled Windows Azure Roles using connect plug-in
  • Install Connect agent on local computers
  • Configure network policy
• Useful Scenarios:
  • Remote administration & troubleshooting
  • Windows Azure Apps Access to on-premise Servers
  • Domain-join Windows Azure roles

Reference : http://msmvps.com/blogs/nunogodinho/archive/2010/11/15/understanding-windows-azure-connect-pdc10-session-review.aspx
By: Anthony Chavez – Director @ Windows Azure Networking Group
Author : NunoGodinho

Watch or Download PDC 10 release Sessions

Hi Friends,

Watch the Sessions at the link given below

http://player.microsoftpdc.com/

You can also download using PDC10 Downloader

http://blogs.msdn.com/b/mark/archive/2010/11/03/pdc10-downloader.aspx

New features per Windows Azure Platform released on 28th Oct 2010

Summary of New 'Windows Azure Platform' features announced at PDC10 Oct. 28th-29th 2010

So, great news at PDC10!. Here I make a summary about new features per Windows Azure Platform pillar (Windows Azure, SQL Azure, AppFabric):

Windows Azure

New Windows Azure Features	State	Description
VM role	Beta in 2010	Eases the migration of existing Windows Server applications to Windows Azure
Extra Small VM	Beta in 2010	For small apps or PoCs
Virtual Network ‘Windows Azure Connect’ is 1st wave (aka. 'Project Sydney')	CTP in 2010	Windows Azure Connect (previously known as “Project Sydney”) enables a simple and easy-to-manage mechanism to set up IP-based network connectivity between on-premises and Windows Azure resources.
Remote Desktop	RTW in 2010	Remote Admin and monitoring
Admin Mode (Elevated privileges)	RTW in 2010	For small changes such as configuring Internet Information Service (IIS) or installing a Microsoft Software Installer (MSI), Microsoft recommends using the Elevated Privileges admin access feature. This approach is best suited for small changes and enables the developer to retain automated service management at the Guest OS and the application level.
Full IIS Support	RTW in 2010	Enables multiple IIS sites per Web role and the ability to install IIS modules
Multiple WA account  Admins	RTW in 2010	Multiple Windows Live IDs admins
CDN Dynamic Content Caching	In 2011	Windows Azure CDN can be configured to cache content returned from a Windows Azure application
CDN SSL	In 2011	Deliver content via encrypted channels with SSL/TLS
New Windows Azure portal	In 2010	Redesigned Microsoft Silverlight-based Windows Azure portal

SQL Azure

New SQL Azure Features	State	Description
SQL Azure Reporting	CTP	Developers can author reports using familiar SQL Server  Reporting Services tools and then easily provision and deploy reports into the cloud.
SQL Azure Data Sync	CTP 2	Enables to synchronize SQL Azure databases across datacenters as well as with on-premises SQL Server. (Entire databases or specific tables)
Database manager for SQL Azure (aka. Houston)	RTW in 2010	New lightweight, web-based database management and querying capability for SQL Azure databases. I was formerly referred to as “Project Houston”, and allows customers to have a streamlined experience within the web browser without having to download any tools.

Windows Azure App Fabric 

New AppFabric Building Blocks	State	Description
AppFabric Cache	CTP at PDC RTW in 2011	Distributed, in-memory application cache, like Windows Server AppFabric Cache (Velocity) but in windows Azure.
Durable messaging in Service Bus (CTP at PDC)	CTP at PDC RTW in 2011	Higher enterprise reliability, giving improved delivery assurance for messages to third-parties or mobile devices
Integration (CTP in CY11) Common BizTalk Server integration capabilities	CTP in CY11	Pipeline, transforms, adapters, BAM and rules, etc.
Composition Model and Tools	CTP in CY11	Will help developers compose applications on the Windows Azure Platform with extensions to the .NET Framework and tie them all together through a new Microsoft Visual Studio-based designer experience.
Composition Service	CTP in CY11	Allows developers to take the Composition Model and automate the deployment, configuration, control, monitoring, troubleshooting, reporting and optimization of an application without the usual manual steps.

 Other WA related new features  

Other New Features	State	Description
TFS on Windows Azure	CTP In 2011	Visual Studio Team Foundation Server in Windows Azure
Windows Azure MarketPlace	CTP In 2011	A single online marketplace for developers and IT professionals to share, find, buy and sell building block components, training, services, needed to build complete and compelling Windows Azure applications
DataMarket	RTW in 2011	Formerly code-named “Dallas”.  It is really part of the MarketPlace

Reference : http://blogs.msdn.com/b/cesardelatorre/archive/2010/10/28/new-windows-azure-platform-features-announced-at-pdc10-oct-28th-29th-2010.aspx

ASP.Net Coding & Performance Tips

ASP.net Tips

from http://www.codersource.net/asp_net_simple_tips.html

1.Smart navigation

Smart navigation is a little-known Internet Explorer feature that enables the individual controls on your Web forms to maintain focus between postback, as well as allows you to suppress that flicker that occurs as you load the new page.
To turn on this little-known feature, simply set the smartNavigation property of your ASPX page to True. You can also apply the property to all project pages, by adding the tag to the following location within your Web.config file:

<--configuration system.web pages smartNavigation="true"/ /system.web /configuration -->

Note that smart navigation works on only Internet Explorer 5 and above; however, ASP.NET will automatically detect this and serve up the ?smart? code only if the target browser supports it.

Also,I'd personally advise that you test it against any third-party menu controls or scripts you may have running: it is prone to falling over on particularly advanced pages.

2.Stopping Your User from Right-Clicking

Want to prevent your user from performing any of the other commands available by right-clicking on a Web page in Internet Explorer? It?s not foolproof, but this neat little HTML edit usually does the trick.

Just alter the opening tag of your HTML to the following:

BODY oncontextmenu="return false">

When the menu is requested, the oncontextmenu event runs, and we instantly cancel it using JavaScript. This is especially potent as a method for stopping the user from viewing your source, when used in conjunction with a menu-less browser window. Great stuff!

3.Creating Images Dynamically

Ask any ASP developer who has ever tried to dynamically create his own images and he?ll tell you it?s a nightmare. In fact, it?s more than a nightmare. It?s practically hell. The only true solution? Reverting to an expensive, dodgy, third-party control to do the work for you.

With ASP.NET, however, you can develop your own dynamic images with ease. Simply create an image object and use the new GDI+ features to add objects to that image, such as text, rectangles, and ellipses. After that, you can simply stream straight back down to the client.

But covering the graphics features in depth would require at least another two books, and, unfortunately, we don?t have that much room. So, I?m going to share a sample that demonstrates creating a small ?Drawing? button, alongside a little blue-and-yellow bullet point.It?s the sort of personalized graphic you?ll find on sites such as Amazon.com.

Here's the code:

Bitmap objBitmap = new Bitmap(120, 30);
Graphics objGraphics = Graphics.FromImage(objBitmap);
objGraphics.FillRectangle(new SolidBrush(Color.LightBlue), 0, 0, 120, 30);
objGraphics.FillEllipse(new SolidBrush(Color.Blue), 3, 9, 10, 10);
objGraphics.FillEllipse(new SolidBrush(Color.Yellow), 4, 10, 8, 8);
objGraphics.DrawString("Drawing", new Font("Tahoma", 8), new SolidBrush(Color.Green), 16, 8);
Response.Clear();
Response.ContentType = "image/jpeg";
objBitmap.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
objGraphics.Dispose();
objBitmap.Dispose();

You can put it inside any event you want.

4.Clear All The Textbox Values (Reset Function)

In Classic ASP, to clear all the textboxes in a form, to start over, we just had to use a simple html 'Reset' button in the form. Sometimes that works in ASP.Net;sometimes it doesn't.

Here are a couple of ways to do this, iterating through the ASP.Net TextBox controls in a form --
Just create a Reset type subroutine - in that routine, use the following code:
in C# - it would be:

Control myForm = Page.FindControl("Form1");
foreach (Control ctl in myForm.Controls)
if(ctl.GetType().ToString().Equals("System.Web.UI.WebControls.TextBox"))
((TextBox)ctl).Text = "";

This will clear EVERYTHING from the textboxes - even if you had them pre-populated with data. A VERY simple way to just reset it to the condition at Page_Load time, just do this in the Reset SubRoutine:

Server.Transfer("YourPageName.aspx")

5.Pressing Enter key

Sometimes, you will notice, that, in an ASP.Net form, depending on the circumstances, pressing the 'Enter' key to submit the form does not work.

To force this to happen for a particular button on your page, just put this in the Page_Load routine:

Page.RegisterHiddenField("__EVENTTARGET", "button1")

Then, change 'button1' to the ID of your particular button. Understand, of course, if your cursor is inside of a MultiLine textbox, the default action of the enter key is to create a new line in the textbox, so, if this basically works anywhere outside of that scenario.
6.ASP.Net Server Controls Not Showing on pages

It's possible that ASP.Net is not registered correctly on your system.Try running aspnet_regiis from the command prompt
.

Here's the default location:

C:\WINNT\Microsoft.NET\Framework\<>\aspnet_regiis.exe -i

Windows Server 2003, you must use aspnet_regiis -i -enable. This is because of the "Web Service Extensions" feature in IIS 6

7.Where To Store Database Connection

Let's say you have a database connection (or several) that you will be using over and over. Yes, you can manually copy/type it in on every ASP.Net page - BUT - an easier way is to store it in the Web.Config file (formerly config.web) and then refer to it in the code.

In Web.Config, you would add a key to the AppSettings Section:

appSettings>
add key="MyDBConnection" value="server=YourServer;uid=Username;pwd=Password;database=DBName" />


for OleDb - use Absolute Path - Not Server.MapPath:
add key="NWOleDB" value= "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Inetpub\wwwroot\data\northwind.mdb;" />

Then, in your ASP.Net application - just refer to it like this:

SqlConnection myConnection = new SqlConnection(ConfigurationSettings.AppSettings("MyDBConnection"));

Quick Tips For ASP.Net

from http://simpable.com/code/quick-tips-for-asp-net-part-one/

written by Scott Watermasysk on Thursday, February 15 2007

Just about everyone has been to a session on ASP.Net best practices, read a book or 10 on the subject, and possibly even a couple of blog posts or MSDN articles. This post is NOT one of them. It is simply a quick list of tips and suggestions for making your ASP.Net application a little better.

I jotted down the tips below over the course of the morning. It is by no means exhaustive and I hope to publish another set of tips or two shortly. If you have any other suggestions/tips, please list them below. If you are not the kind of person who likes to comment on a blog, please drop me a line at scottwater@gmail.com. I will either add them below or create another post and list them. I am also working on a set of caching tips, so if you have any of them, there will be a specific post related to caching.

Tip: Do not use the AutoPostBack attribute on the DropDownList control to simply redirect to another page.

There are probably cases when this might make sense, but for the most part it is overkill. Using the autopostback for a redirect requires extra roundtrip to the server. First the autopostback returns to the server and processes everything up to the event handling the postback. Next a Response.Redirect is issued which goes back to the client requesting the client use another page. So you end up with two separate requests + processing just to get a user to another page.

Using the onchange event of the select element, we can do this all on the client. In the sample below, I am simply redirecting to the current page with an updated querystring element. Your logic will vary, but in the case below, I am avoiding the zero index.

0) { window.location = window.location.pathname + '?t=' + this[this.selectedIndex].value;}" />

Tip: Never use the ASP.Net Label control.

Ever is a strong word, but except for some quick and dirty style hacks you should never ever use this control. Any text is rendered inside a span control which is usually unnecessary and complicates any CSS styling you may be trying to use. In most cases, you can replace the Label with a Literal and achieve the same results.

Tip: Use the ASP.Net Repeater instead of DataList, DataGrid, and DataView controls

The Repeater is the single most powerful control shipped in ASP.NET. It is versatile and lightweight. There are times (especially prototyping) when the other databound controls make sense to use, but they generate a lot of extra markup and generally complicate the page with all of their events and styling. Using the Repeater, you may write a little more code up front, but you will be rewarded in the long run.

Tip: Understand how to effectively use caching.

By now, most ASP.NET developers know about the Cache. Most examples show the virtue of caching for hours at a time. Very little data that is worth the effort to display on a web page requires caching for this long. The main reasons for caching are performance related. Memory in ASP.NET is still a very limited resource. Do not waste it by caching anything more than a couple of minutes unless it is very expensive to regenerate.

Tip: Always set a memory threshold for your AppPool.

A related tip would be to first understand the total memory available on your box: how many sites are there, is SQL running locally? Is there anything else on this box which will consistently use Memory?

In most cases, you should never set the available memory for an AppPool above 800mb's unless you can also set the 3/gb switch (then you can use about 1200mb). Allowing memory to go unchecked or set about 800mb can bring even a moderately sized site to it's knees once too much memory is used.

Tip: Use AppOffline.htm for updates

If you are making any changes to files in your bin directory, always use the AppOffline.htm file. It is very likely that while you uploading (or copy & pasting) your updates, users will see an error message. It is much better to show them one that you purposely created and can explain the situation vs. the built in ASP.NET error pages (or even your own customError page). In addition, this will help prevent the locking .dll issue that is not supposed to exist anyway.

Tip: Always check Page.IsValid in your button's EventHandler.

Just because you are using ASP.Net validation controls, do not assume the page could not be submitted with invalid data.

Also, just because you hide a control, do not assume buttons/textboxes/etc on it are not submit-able. It is perfectly fine to hide a control that a user should not access, but with very little code (or using a third party tool) users can easily make an HttpPost with any data they choose.

Tip: When redirects are permanent, use a 301 status code.

This use to be a little more manual, but with ASP.NET 2.0, it is even easier:

Response.RedirectLocation = "http://site.com/newlink.aspx";
Response.End();

Tip: To create fully qualified URLs, use the new VirtualPath class.

string relativePath = "~/somefolder/test/123.aspx"
Uri newUri = new Uri(Request.Url, VirtualPathUtility.ToAbsolute(relativePath));

Again, please add any other suggestions below. I am looking forward to reading them.

Update: It looks like there is a case for using the Label control as an html label element (for accessibility). I was unaware of this functionality and will call it out better in another tip installment. Thanks Phil and Dusty!

Regular Expressions in .Net

Hi friends,

Want to get Regular Expressions for your Custom Validator in .Net, go to the Link below.

http://regexlib.com/

How do I catch the RowIndex in GridView RowCommand event?

The Solution for catching it is as below

Hi,

In row command if you want to get the current row or its index, It is not directly possible. There is two way, one is on row created event on the link button(suppose, it is used for row command) save row index in link button command argument attribute.

And get the argument from row command event using e.CommandArgument

But if you want to send another value as a command argument then it creates problem. To solve this just use this code

GridViewRow row = (GridViewRow)(((LinkButton)e.CommandSource).NamingContainer);

Here link button (or any source) that cause to enter in row command event. Now you have selected row so you don’t need any index and directly access any row variable as sample code is given below
Label lblProdId = (Label)row.FindControl(”lblproductId”);

So whole code is just two line. Below I write whole code

-------------------------------------------------------------------------------
GridViewRow row = (GridViewRow)(((LinkButton)e.CommandSource).NamingContainer);

Label lblProdId = (Label)row.FindControl(”lblproductId”);

-------------------------------------------------------------------------------
Source from : http://ranafaisal.wordpress.com/2008/03/31/how-to-get-the-current-row-in-gridview-row-command-event/

How to add a default ListItem to a DropDownList

This can be done one of 2 ways. A default ListItem can be added to a DropDownList programmatically with the following syntax after binding data to the DropDownList:


//Code here to populate DropDownList

DropDownListID.Items.Insert(0, new ListItem("Default text", "Default value")

This will add a ListItem to index 0, which will be the first ListItem.

In .NET 2.0, this can be done declaratively using the AppendDataBoundItems property. This will append all data-bound ListItems to the DropDownList, leaving those you add manually as the first selections.




Solution by : Ryan Olshan
ASPInsider | Microsoft MVP, ASP.NET
http://ryanolshan.com

Windows Communication Foundation Architecture

Windows Communication Foundation Architecture
The following graphic illustrates the major layers of the Windows Communication Foundation (WCF) architecture.


WCF Architecture



Contracts and Descriptions
Contracts define various aspects of the message system. The data contract describes every parameter that makes up every message that a service can create or consume. The message parameters are defined by XML Schema definition language (XSD) documents, enabling any system that understands XML to process the documents. The message contract defines specific message parts using SOAP protocols, and allows finer-grained control over parts of the message, when interoperability demands such precision. The service contract specifies the actual method signatures of the service, and is distributed as an interface in one of the supported programming languages, such as Visual Basic or Visual C#.

Policies and bindings stipulate the conditions required to communicate with a service. For example, the binding must (at a minimum) specify the transport used (for example, HTTP or TCP), and an encoding. Policies include security requirements and other conditions that must be met to communicate with a service.

Service Runtime
The service runtime layer contains the behaviors that occur only during the actual operation of the service, that is, the runtime behaviors of the service. Throttling controls how many messages are processed, which can be varied if the demand for the service grows to a preset limit. An error behavior specifies what occurs when an internal error occurs on the service, for example, by controlling what information is communicated to the client. (Too much information can give a malicious user an advantage in mounting an attack.) Metadata behavior governs how and whether metadata is made available to the outside world. Instance behavior specifies how many instances of the service can be run (for example, a singleton specifies only one instance to process all messages). Transaction behavior enables the rollback of transacted operations if a failure occurs. Dispatch behavior is the control of how a message is processed by the WCF infrastructure.

Extensibility enables customization of runtime processes. For example, message inspection is the facility to inspect parts of a message, and parameter filtering enables preset actions to occur based on filters acting on message headers.

Messaging
The messaging layer is composed of channels. A channel is a component that processes a message in some way, for example, by authenticating a message. A set of channels is also known as a channel stack. Channels operate on messages and message headers. This is different from the service runtime layer, which is primarily concerned about processing the contents of message bodies.

There are two types of channels: transport channels and protocol channels.
Transport channels read and write messages from the network (or some other communication point with the outside world). Some transports use an encoder to convert messages (which are represented as XML Infosets) to and from the byte stream representation used by the network. Examples of transports are HTTP, named pipes, TCP, and MSMQ. Examples of encodings are XML and optimized binary.
Protocol channels implement message processing protocols, often by reading or writing additional headers to the message. Examples of such protocols include WS-Security and WS-Reliability.

The messaging layer illustrates the possible formats and exchange patterns of the data. WS-Security is an implementation of the WS-Security specification enabling security at the message layer. The WS-Reliable Messaging channel enables the guarantee of message delivery. The encoders present a variety of encodings that can be used to suit the needs of the message. The HTTP channel specifies that the HyperText Transport Protocol is used for message delivery. The TCP channel similarly specifies the TCP protocol. The Transaction Flow channel governs transacted message patterns. The Named Pipe channel enables interprocess communication. The MSMQ channel enables interoperation with MSMQ applications.

Hosting and Activation

In its final form, a service is a program. Like other programs, a service must be run in an executable. This is known as a self-hosted service.

Services can also be hosted, or run in an executable managed by an external agent, such as IIS or Windows Activation Service (WAS). WAS enables WCF applications to be activated automatically when deployed on a computer running WAS. Services can also be manually run as executables (.exe files). A service can also be run automatically as a Windows service. COM+ components can also be hosted as WCF services.

See Also
Concepts
What Is Windows Communication Foundation?
Fundamental Windows Communication Foundation Concepts

Service Oriented Architecture

A service-oriented architecture (SOA) is the underlying structure supporting communications between services. In this context, a service is defined as a unit of work to be performed on behalf of some computing entity, such as a human user or another program. SOA defines how two computing entities, such as programs, interact in such a way as to enable one entity to perform a unit of work on behalf of another entity. Service interactions are defined using a description language. Each interaction is self-contained and loosely coupled, so that each interaction is independent of any other interaction.

Simple Object Access Protocol (SOAP)-based Web services are becoming the most common implementation of SOA. However, there are non-Web services implementations of SOA that provide similar benefits. The protocol independence of SOA means that different consumers can communicate with the service in different ways. Ideally, there should be a management layer between the providers and consumers to ensure complete flexibility regarding implementation protocols.

Whether you realize it or not, you've probably relied upon SOA, perhaps when you made a purchase online. Let's use Land's End as an example. You look at their catalog and choose a number of items. You specify your order through one service, which communicates with an inventory service to find out if the items you've requested are available in the sizes and colors that you want. Your order and shipping details are submitted to another service which calculates your total, tells you when your order should arrive and furnishes a tracking number that, through another service, will allow you to keep track of your order's status and location en route to your door. The entire process, from the initial order to its delivery, is managed by communications between the Web services -- programs talking to other programs, all made possible by the underlying framework that SOA provides.
___________________________________________________________________

Abbreviated SOA, an application architecture in which all functions, or services, are defined using a description language and have invokable interfaces that are called to perform business processes. Each interaction is independent of each and every other interaction and the interconnect protocols of the communicating devices (i.e., the infrastructure components that determine the communication system do not affect the interfaces). Because interfaces are platform-independent, a client from any device using any operating system in any language can use the service.

XML Though built on similar principles, SOA is not the same as Web services, which indicates a collection of technologies, such as SOAP and XML. SOA is more than a set of technologies and runs independent of any specific technologies.

____________________________________________________________________

A service-oriented architecture is essentially a collection of services. These services communicate with each other. The communication can involve either simple data passing or it could involve two or more services coordinating some activity. Some means of connecting services to each other is needed. The combination of services - internal and external to an organization - makes up a service-oriented architecture.

If a service-oriented architecture is to be effective, we need a clear understanding of the term service. A service is a function that is well-defined, self-contained, and does not depend on the context or state of other services. Services are what you connect together using Web Services. A service is the endpoint of a connection. Also, a service has some type of underlying computer system that supports the connection offered.

The technology of Web Services is the most likely connection technology of service-oriented architectures. Web services essentially use XML to create a robust connection.

______________________________________________________________

http://15seconds.com/issue/031215.htm

http://www.c-sharpcorner.com/UploadFile/john_charles/
Service_Oriented_Architecture_and_Microsoft_NET01202006080616AM/
Service_Oriented_Architecture_and_Microsoft_NET.aspx

http://msdn2.microsoft.com/en-us/architecture/aa948857.aspx

http://www.devshed.com/c/a/Web-Services/Introduction-to-Service-Oriented-Architecture-SOA/