All communication with a Windows Communication Foundation (WCF) service occurs through the endpoints of the service. Endpoints provide clients access to the functionality offered by a WCF service.
Each endpoint consists of four properties:
An address that indicates where the endpoint can be found.
A binding that specifies how a client can communicate with the endpoint.
A contract that identifies the operations available.
A set of behaviors that specify local implementation details of the endpoint.
You have to define end point in web.config like e.g.
<system.serviceModel>
<bindings>
<basicHttpBinding>
<binding name="BasicHttpBinding_IPairArihmeticService"/>
</basicHttpBinding>
</bindings>
<client>
<endpoint address="http://localhost:1062/WcfTestWebSite/PairArihmeticService.svc"
binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_IPairArihmeticService"
contract="PairServiceReference.IPairArihmeticService"
name="BasicHttpBinding_IPairArihmeticService"/>
</client>
</system.serviceModel>