Demo Script
Windows Azure Service Bus NetTcpRelayBinding Hybrid mode
Version:
2.0.0
Last updated:
3/23/2016
Contents
OVERVIEW ................................................................................................................................................... 3
Key Messages ........................................................................................................................................... 3
Key Technologies ...................................................................................................................................... 3
Time Estimates ......................................................................................................................................... 4
SETUP AND CONFIGURATION .................................................................................................................. 4
Task 1 – Creating a Service Bus Namespace ......................................................................................... 4
Task 2 – Opening the Direct Connection Sample.................................................................................. 4
DEMO FLOW ................................................................................................................................................ 5
OPENING STATEMENT............................................................................................................................... 6
STEP-BY-STEP WALKTHROUGH .............................................................................................................. 6
Looking at the code in Visual Studio ......................................................................................................... 6
Run the code ............................................................................................................................................. 8
SUMMARY .................................................................................................................................................... 9
KNOWN ISSUES ........................................................................................................................................ 10
Overview
This demo shows the Service Bus NetTcpRelayBinding using Hybrid connection mode. When this works correctly, a direct connection is
established between the client and service and the Service Bus is bypassed, increasing throughput.
The code is part of the Windows Azure SDK samples that you can download from http://code.msdn.microsoft.com/windowsazure.
Note: In order to run through this complete demo, you must have network connectivity and a Service Bus namespace.
Key Messages
1. It is very simple for a .NET developer to modify a typical WCF app to use the .NET Service Bus
2. This binding gives you the highest performance and throughput and hybrid mode enables direct connections.
Key Technologies
This demo uses the following technologies:
1. .NET Framework 3.5 SP1
2. Visual Studio 2010
3. Windows Azure Libraries for .NET
4. Windows Azure Service Bus (i.e. internet connectivity is required)
Time Estimates

Estimated time for setting up and configuring the demo: 5 min

Estimated time to complete the demo: 5 min
Setup and Configuration
This demo does not have any advanced configuration requirements. Make sure you have checked all the dependencies for this demo and have a
Windows Azure account. For more information on how to purchase an account, visit the Windows Azure Portal at https://windows.azure.com/.
Task 1 – Creating a Service Bus Namespace
1. Navigate to the Windows Azure Management Portal. You will be prompted for your Windows Live ID credentials if you are not already
signed in.
2. Click Service Bus, Access Control & Caching link in the left pane, and then select “Service Bus” item under Services element.
3. Create a Service Namespace.
Task 2 – Opening the Direct Connection Sample
1. Download the Relayed Messaging Bindings: NetTcp Direct from http://code.msdn.microsoft.com/Relayed-Messaging-Bindingsca039161.
2. Open Visual Studio running as administrator. Open the DirectConnnectionSample solution located in the zip file downloaded in the
previous step.
3. Test the direct connection where you’re located to see if it works so that you’re not surprised when you run it in front of an audience.
Demo Flow
The following diagram illustrates the high-level flow for this demo and the steps involved:
Figure 1
Diagram
Opening Statement
This demo shows how it’s possible to establish a direct connection between client and service using the Service Bus, even if they’re behind
firewalls and NATs.
Step-by-Step Walkthrough
This demo is composed of the following segments:
1. Show the code in Visual Studio
2. Run the code
Looking at the code in Visual Studio
Action
Script
1. Open the DirectConnectionSample in
Visual Studio

2. Open the (service) HelloContract.cs
This is the service contract. It’s a
simple one-way contract with some
text being sent from the client to the
service.
Screenshot
3. Open HelloService.cs

Here is the service implementation –
it does not do anything!
4. Open the service App.config

In the App.config you can see we are
using the netTcpRelayBinding and
the connectionMode is set to
“Hybrid". This means that we’ll try to
establish a direct connection but if it’s
not possible we’ll continue to
communicate via the ServiceBus. The
other connection mode is:
Relayed – go through the bus
5. Open service Program.cs

In the main program we have the
standard code for creating a host.
We’re using a “sb://”-based URI and
username and password
authentication.
6. Open client App.config

The client is set up the same way, to
use “Hybrid” mode with
netTcpRelayBinding
7. Open client Program.cs

The client app sends messages in a
tight loop and every 250 milliseconds
reports how many messages were
sent in that time.
8. Show the ConnectionStateChanged
event handler.

There is a ConnectionStateChanged
event raised when the connection
state changes. In our case, if we go
from relayed to direct we’ll get an
“Upgraded!” message in the console
window.
Run the code
Action
Script
9. Right click Service in the Solution
Explorer and select Debug > Start
new instance

10. Enter the Service Namespace,
11. Entre the issuer name and key.
Now we’ll run the application. First
the service…
Screenshot
12. Right click Client in the Solution
Explorer and select Debug > Start
new instance

And now the client…

You can see the number of
messages sent by the client every
quarter of a second.

Now you can see the throughput has
increased as a direct connection has
been established. The Service Bus is
no longer being used.
13. Enter the Service Namespace
14. Enter the issuer name and key
15. Make both console windows visible
16. [When the rate increases]
Summary
This demo showed how clients and services can connect via the Service Bus through firewalls and NATs, and then “upgrade” the connection to a
direct connection by predicting the NAT port allocation. This mode offers much greater throughput and as messages do not go through the
Service Bus there is no throughput charge.
Known Issues
Please note the following known issues with this demo:
Test well before using. The busier the network you’re on, the less likely it is to work.
Of course, if network bandwidth is the limiting factor rather than going via the Service Bus then you won’t see an increase in
throughput.