changed the way ports are added to the server
diff --git a/src/csharp/Grpc.IntegrationTesting/InteropClientServerTest.cs b/src/csharp/Grpc.IntegrationTesting/InteropClientServerTest.cs
index ab38fc8..6fa721b 100644
--- a/src/csharp/Grpc.IntegrationTesting/InteropClientServerTest.cs
+++ b/src/csharp/Grpc.IntegrationTesting/InteropClientServerTest.cs
@@ -33,6 +33,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using grpc.testing;
@@ -47,7 +48,7 @@
     /// </summary>
     public class InteropClientServerTest
     {
-        string host = "localhost";
+        const string Host = "localhost";
         Server server;
         Channel channel;
         TestService.ITestServiceClient client;
@@ -55,18 +56,19 @@
         [TestFixtureSetUp]
         public void Init()
         {
-            server = new Server()
+            server = new Server
             {
-                Services = { TestService.BindService(new TestServiceImpl()) }
+                Services = { TestService.BindService(new TestServiceImpl()) },
+                Ports = { { Host, ServerPort.PickUnused, TestCredentials.CreateTestServerCredentials() } }
             };
-            int port = server.AddPort(host, Server.PickUnusedPort, TestCredentials.CreateTestServerCredentials());
             server.Start();
 
             var options = new List<ChannelOption>
             {
                 new ChannelOption(ChannelOptions.SslTargetNameOverride, TestCredentials.DefaultHostOverride)
             };
-            channel = new Channel(host, port, TestCredentials.CreateTestClientCredentials(true), options);
+            int port = server.Ports.Single().BoundPort;
+            channel = new Channel(Host, port, TestCredentials.CreateTestClientCredentials(true), options);
             client = TestService.NewClient(channel);
         }
 
diff --git a/src/csharp/Grpc.IntegrationTesting/InteropServer.cs b/src/csharp/Grpc.IntegrationTesting/InteropServer.cs
index 05058d6..504fd11 100644
--- a/src/csharp/Grpc.IntegrationTesting/InteropServer.cs
+++ b/src/csharp/Grpc.IntegrationTesting/InteropServer.cs
@@ -97,11 +97,11 @@
             int port = options.port.Value;
             if (options.useTls)
             {
-                server.AddPort(host, port, TestCredentials.CreateTestServerCredentials());
+                server.Ports.Add(host, port, TestCredentials.CreateTestServerCredentials());
             }
             else
             {
-                server.AddPort(host, options.port.Value, ServerCredentials.Insecure);
+                server.Ports.Add(host, options.port.Value, ServerCredentials.Insecure);
             }
             Console.WriteLine("Running server on " + string.Format("{0}:{1}", host, port));
             server.Start();
diff --git a/src/csharp/Grpc.IntegrationTesting/SslCredentialsTest.cs b/src/csharp/Grpc.IntegrationTesting/SslCredentialsTest.cs
index 7c553d5..1c398eb 100644
--- a/src/csharp/Grpc.IntegrationTesting/SslCredentialsTest.cs
+++ b/src/csharp/Grpc.IntegrationTesting/SslCredentialsTest.cs
@@ -34,6 +34,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using grpc.testing;
@@ -49,7 +50,7 @@
     /// </summary>
     public class SslCredentialsTest
     {
-        string host = "localhost";
+        const string Host = "localhost";
         Server server;
         Channel channel;
         TestService.ITestServiceClient client;
@@ -67,9 +68,9 @@
 
             server = new Server
             {
-                Services = { TestService.BindService(new TestServiceImpl()) }
+                Services = { TestService.BindService(new TestServiceImpl()) },
+                Ports = { { Host, ServerPort.PickUnused, serverCredentials } }
             };
-            int port = server.AddPort(host, Server.PickUnusedPort, serverCredentials);
             server.Start();
 
             var options = new List<ChannelOption>
@@ -77,7 +78,7 @@
                 new ChannelOption(ChannelOptions.SslTargetNameOverride, TestCredentials.DefaultHostOverride)
             };
 
-            channel = new Channel(host, port, clientCredentials, options);
+            channel = new Channel(Host, server.Ports.Single().BoundPort, clientCredentials, options);
             client = TestService.NewClient(channel);
         }