Stack having all internal threads frozen would queue the requests/responses indefinitely. We should drop
messages that wait on the queue for too long. The property that control the maximum wait time is
This property replaces gov.nist.javax.sip.CONGESTION_CONTROL_ENABLED which used to drop the latest
requests instead of the oldest with fixed queue size and random drops.
This issues is linked to http://code.google.com/p/mobicents/issues/detail?id=2152