Skip to main content

Azure Service Bus Topics - How communication works over HTTP (80,443)

In this topic we will talk about different protocols and ports that can be used to communicate between our machines and Azure Service Bus Topics.
The communication between Azure Service Bus Topic and our machines we can use:
  • AMQP (new and hot)
  • TCP/IP
  • HTTP
For TCP/IP connection is pretty clear what ports are used (9351 and 9552). It seems that 9351 is used for inbound traffic and 9552 is used for outbound traffic (this ports may change)

The interesting discussion is when we are taking about HTTP. The communication over HTTP protocol is done over two ports - 443 and 80.
Each port is used for specific use case:
  • 80:   is used for outbound traffic
  • 443: is used for inbound traffic
This means that when we are listening to a subscription we will use port 80 to check if a message is available. The same port will be used to receive the message from subscription. 
The port 443 is used when we need to send messages to topic. Each time when we send a message to a topic, the message is send over 443 without exception. 

For both ports (80 and 443), the communication is done done using a TLS/SSL. Even if port 80 is used, the communication is secure - inside a tunnel. No data in clear are send between our application and Azure Service Bus.
It is important to know that Azure Service Bus doesn't supports unsecure connection. All the communication will be done over a secure tunnel.

If the connectivity mode is not change (AutoDetect), the Azure Service Bus library will try to use TCP/IP connection. If the connection cannot be established using the 9XXX ports, it will fall back automatically to HTTP ports.
We have the possibility to specify directly what kind of connectivity mode we want to use (AutoDetect/TCP/HTTP). This is useful when we already know the connectivity type. 
The below sample shows how we can configure it.
HTTP: ServiceBusEnvironment.SystemConnectivity.Mode = ConnectivityMode.Http;
TCP:  ServiceBusEnvironment.SystemConnectivity.Mode = ConnectivityMode.Tcp;
Auto: ServiceBusEnvironment.SystemConnectivity.Mode = ConnectivityMode.AutoDetect;

In conclusion we should keep in mind that all the communication between Azure Service Bus endpoint and our system is done over a secure channel. For HTTP connection, a tunnel is establish over 80 and 443 ports.


Popular posts from this blog

ADO.NET provider with invariant name 'System.Data.SqlClient' could not be loaded

Today blog post will be started with the following error when running DB tests on the CI machine:
threw exception: System.InvalidOperationException: The Entity Framework provider type 'System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer' registered in the application config file for the ADO.NET provider with invariant name 'System.Data.SqlClient' could not be loaded. Make sure that the assembly-qualified name is used and that the assembly is available to the running application. See for more information. at System.Data.Entity.Infrastructure.DependencyResolution.ProviderServicesFactory.GetInstance(String providerTypeName, String providerInvariantName) This error happened only on the Continuous Integration machine. On the devs machines, everything has fine. The classic problem – on my machine it’s working. The CI has the following configuration:

TeamCity.NET 4.51EF 6.0.2VS2013
It seems that there …

How to check in AngularJS if a service was register or not

There are cases when you need to check in a service or a controller was register in AngularJS.
For example a valid use case is when you have the same implementation running on multiple application. In this case, you may want to intercept the HTTP provider and add a custom step there. This step don’t needs to run on all the application, only in the one where the service exist and register.
A solution for this case would be to have a flag in the configuration that specify this. In the core you would have an IF that would check the value of this flag.
Another solution is to check if a specific service was register in AngularJS or not. If the service was register that you would execute your own logic.
To check if a service was register or not in AngularJS container you need to call the ‘has’ method of ‘inhector’. It will return TRUE if the service was register.
if ($injector.has('httpInterceptorService')) { $httpProvider.interceptors.push('httpInterceptorService&#…

Fundamental Books of a Software Engineer (version 2018)

More then six years ago I wrote a blog post about fundamental books that any software engineer (developer) should read. Now it is an excellent time to update this list with new entries.

There are 5 different categories of books, that represent the recommended path. For example, you start with Coding books, after that, you read books about Programming, Design and so on.
There are some books about C++ that I recommend not because you shall know C++, only because the concepts that you can learn from it.


Writing solid codeCode completeProgramming Pearls, more programming pearls(recommended)[NEW] Introduction to Algorithms


Refactoring (M. Fowler)Pragmatic ProgrammerClean code[NEW] Software Engineering: A Practitioner's Approach[NEW] The Mythical Man-Month[NEW] The Art of Computer Programming


Applying UML and Patterns (GRASP patterns)C++ coding standards (Sutter, Alexandrescu)The C++ programming language (Stroustrup, Part IV)Object-oriented programming (Peter Coad)P…