Timedout class3 closes its underlying TCP even if other class3 connections running over the same TCP

After a connection timeout, to close the underlying TCP we have to check all dependencies to the TCP which means to check if are there any other class1/3 connections opened via the same TCP connections. 
We currently only check if there are IO connections still running and opened via the same TCP.  It means having multiple parallel class3 connections, when one of them times out, the TCP will be closed! 

In the following pcap image, there are three class connections with timeouts of 400mS, 800mS and 1200mS. when the 400mS Connection times out, it closes consequently the underlying shared TCP connection.