I wondered if any users on here have experienced this strange hold issue. I have put a call into our reseller, but in the mean time I thought I would ask this very knowledgeable forum.
The situation is this:-
A calls B - B places A on hold. A hears MOH and B sees held alert on handset display.
B takes A off hold.
Now if A places B on hold, the hold works but no MOH is heard at B and no Held alert is displayed on A.
The hold can be cancelled no problem.
The customers are blissfully unaware of any problems as the hold functions work correctly. The more eagle eyed amongst them may realise that they are missing MOH after the second hold.
SIP traces indicate that the first hold by the B device, results in a 200 OK / ACK loop. This is only broken when the B device places A on hold again.
We have recreated this fault on both live and test platforms, which use a mixture of equipment types. Primarily our test handsets are Polycom3xx with old SIP 3.2.0 and 3.2.3 applications.
The fault is not replicated on SNOM handsets used on the live and test environments.
I have good and bad SIP traces should anybody care to examine them.
there a various tweaks that can be used for hold scenarios.
I would suggest you update your Phones to a later software version as 3.2.7 or 3.3.5 is the latest for the 320/330 or UCS 4.1.0 for the 321/331/335 range.