In the following screenshot, we see the reason for an application freeze:

In the example, we make the following observations:

• A client with an IP address that starts with 203 is trying to connect to NAS01SAMIM on a server with an IP address 10.1.70.95, and gets back a STATUS_ACCESS_DENIED error
• The server on 10.1.70.95 answers that the access is denied
• Since the application waits, TCP is holding the connection with keep-alive messages
• After a while, the client sends disconnect request that is approved by the server
• The application waits and TCP maintains the connection with keep-alive
• TCP closes the connection with RST (reset)

What the customer saw here was an application freeze.