Ashok,
I recommend that You have:
Set sc = workMgr.Queue("..Cleanup",QueueId)
and also:
Set sc = workMgr.WaitForComplete() 
Do workMgr.Clear()
All this will ensure a relegable and smooth completion of the queue manager.
We never used any hung when adding tasks into the queue.

Hi Ashok,

For the queue manager to recognize a proper completion of any code, it should be defined as a function.
If you test the sc for subr1 you will see a <PARAMETER> error. This is why the () is required.
It is better to have a quit $$$OK (or Quit 1) at the end, but this is not mandatory.

Intersystems UDP implementation (e.g. EnsLib.UDP.OutboundAdapter) is assuming that any stream<MTU size: it uses stream.OutputToDevice() so it will not work with streams>MTU

when splitting parts, consider packet can arrived at random order, so you should "collect" them at receiver, then build the incoming message according to the correct order when you know you have them all