Connection crossing can block programs indefinitely

The comments in the code explain how crossing connections are resolved.

This solution, unfortunately, does not account for the possibility of connection failures.

It can be that A has a severed connection to B, but A still thinks the connection is healthy. Now, B is aware that the connection has failed, and it tries to reconnect. The result is that A will respond with ConnectionRequestCrossed, and B will wait forever an incoming connection from A.