Another reason for retransmissions can be when a client or a server does not answer to requests. In this case, you will see five retransmissions, with an increasing time difference. After these five consecutive retransmissions, the connection is considered to be lost by the sending side (in some cases, reset will be sent to close the connection depending on the software implementation). After the disconnection, two things may happen:

• An SYN request will be sent by the client in order to open a new connection. What the user will see in this case is a freeze in the application, and after 15-20 seconds, it will start to work again.
• No SYN will be sent, and the user will have to run the application (or a specific part of it) again.

In the following screenshot, we can see a case in which a new connection is opened: