Default Port for SQL Server

TCP 1433

TCP port 1433 is the default port for SQL Server. Client machine will be using TCP 1433 to connect to the database engine of the server. If the port is not available, SQL Server will be listening on a different available port.

UDP 1434

SQL Server Browser services compatible port is UDP port 1434 and it's used for SQL Server named instances. In practical, the services responds to the client request with the TCP port number for the requested named instance.

TCP 2383

For Analysis Services TCP port 2383 is used.