How do I find out if I'm using SBMP or AMQP protocol?

Question

I got an email saying that support for SBMP protocol is going to end for the library WindowsAzure.ServiceBus in September 2026. I'm trying to check if my code uses this protocol, but I'm having trouble finding documentation on this. How do I find out what protocol I'm using? Where does this get configured?

Answer 1

Hi Ian, thanks for reaching out.

If you are leveraging the WindowsAzure.ServiceBus libraries, by default it will use SBMP protocol unless explicitly changed. You can change it by modifying the transport type option https://learn.microsoft.com/en-us/dotnet/api/microsoft.servicebus.messaging.transporttype?view=azure-dotnet-legacy

connectionStringBuilder.TransportType = TransportType.Amqp 

See another example below

using Microsoft.ServiceBus;
using Microsoft.ServiceBus.Messaging;

// Create the connection string builder
var connectionStringBuilder = new ServiceBusConnectionStringBuilder("your_connection_string");

// Check the transport type
TransportType transportType = connectionStringBuilder.TransportType;

if (transportType == TransportType.NetMessaging)
{
    Console.WriteLine("Using SBMP (Service Bus Messaging Protocol).");
}
else if (transportType == TransportType.Amqp)
{
    Console.WriteLine("Using AMQP (Advanced Message Queuing Protocol).");
}
else
{
    Console.WriteLine("Unknown transport type.");
}

// Optionally, set the transport type if needed
connectionStringBuilder.TransportType = TransportType.NetMessaging;

// Create a QueueClient with the specified transport type
QueueClient queueClient = QueueClient.CreateFromConnectionString(connectionStringBuilder.ToString());

We do recommend migrating to the latest SDKs for Service Bus, as the legacy ones are deprecated and do not receive updates, newest SDK can only use the AMQP protocol and receive constant improvements throughout the year.