<configuration>
    <system.web>
        <compilation debug="true" />
    </system.web>
    <system.serviceModel>
        <services>
            <service name="NetTcpServiceToHostinWindowsServices.Service1" behaviorConfiguration="MyBehavior">
                <host>
                    <baseAddresses>
                        <add baseAddress = "net.tcp://localhost:9999/Service1/" />
                    </baseAddresses>
                </host>
                <endpoint name ="NetTcpEndPoint"
                          address =""
                          binding="netTcpBinding"
                          bindingConfiguration="StreamedNet"
                          contract="NetTcpServiceToHostinWindowsServices.IService1">
                </endpoint>
                <endpoint name ="NetTcpMetadataPoint"
                          address="mex"
                          binding="mexTcpBinding"
                          contract="IMetadataExchange"/>
            </service>
        </services>
        <behaviors>
            <serviceBehaviors>
                <behavior name ="MyBehavior">
                    <serviceMetadata httpGetEnabled="False"/>
                    <serviceDebug includeExceptionDetailInFaults="False" />
                </behavior>
            </serviceBehaviors>
        </behaviors>

        <bindings>
            <netTcpBinding>
                <binding 
                    name="StreamedNet"
                    maxReceivedMessageSize="2147483647" 
                    transferMode="Streamed" />
            </netTcpBinding>
        </bindings>
        
    </system.serviceModel>
</configuration>

<configuration>
    <system.serviceModel>
        
        <client>
            <endpoint address="net.tcp://localhost:9999/Service1/" binding="netTcpBinding"
                bindingConfiguration="StreamedNet" contract="ServiceReference1.IService1"
                name="NetTcpEndPoint">
                <identity>
                    <userPrincipalName value="nome.cognome@dominio.local" />
                </identity>
            </endpoint>
        </client>
        
        <bindings>
            <netTcpBinding>
                <binding name="StreamedNet" transferMode="Streamed" maxReceivedMessageSize="2147483647" />
            </netTcpBinding>
        </bindings>
        
    </system.serviceModel>
</configuration>

[ServiceContract]
    public interface IService1 {
        [OperationContract]
        Stream GetStreamFile();
    }

public class Service1 : IService1 {

         Stream GetStreamFile() {
            
            string filePath = @"fullpath_del_file";

            FileStream fs = null;

            try {
                fs = File.OpenRead(filePath);                
            }
            catch (Exception ex) { }
            return fs;
        }
        
    }