Archived:Receiving and sending threads on a single UDP connection block each other (Known Issue)
When using two threads on a single UDP connection, receiving and sending block each other.
When using two threads on a single UDP connection, receiving and sending block each other. If an application sets up the receiving thread before sending the first packet, then it will become deadlocked. Also, while it is waiting for a response from the server, it can't retry sending.
Use an alternative implementation method. If possible, always set up a sending thread first.
This is fixed in newer Series 40 3rd Edition devices.