Windows Communication Framework (WCF) is a unifying technology that includes various service technologies and provides one interface under one service. WCF is the Microsoft technology to realize the Service Oriented Architecture (SOA) vision. WCF is a very flexible technology that can be implemented as a Windows Service. It can be consumed by different clients like Windows forms, Silverlight applications, and ASP.NET pages.

This chapter will introduce how to create a service using WCF and then consume it in Phone 7 apps. We will cover different options available to access the data layer. We will learn how the Entity Framework or (EF) can be used and then LINQ to SQL technologies.