When error The semaphore timeout period has expired displays, make note of the details of the timeout in the yellow area of the error message. In this example, the following details are displayed in the yellow area of the error message: SqlException 0x80131904 A transport-level error has occurred when receiving results from the server.
Notice this error clearly identifies an issue with the transport layer.
The transport layer is the third layer in the TCP/IP model.
Notice also the error signifies a SQL Exception. If you are using a hosting providers SQL Server, contact the hosting provider to determine if the hosting providers SQL Server is having issues. If this error only occurs intermittently, there certainly is not a problem with the code of your application, and there is indeed some issues along the path with with the SQL Server.