Sprint cell phone does not pass ringing when forwarded on a 7316e

[MACGVEYER]

I have a new Norstar MICS system, all is fine, except for call forwarding to a sprint cell phone. When I set the call forward feature to on to a sprint cell phone (in a 7316e handset) and have a call come in thru a DID line to that handset, the call does get forwarded, but the "ringing" that a caller normally hears does not follow..they hear dead silence, but the receiving sprint phone does indeed start ringing, and when picked up, the call does complete.(FYI...this is a national issue for us)
No other cell phone network has this problem, if forward is set to a Verizon cell phone, the caller hears it ringing, and the cell phone rings as well, BUT not on a sprint cell, the caller hears dead silence, but the cell phone is ringing.
It has stumped AT&T, SPRINT, my PBX installer, for the last 4 months.
I suspect a timing issue in my new MICS, since all was well before it was installed, but I do not know what I can change to extend the timing to have it switch the call to the Sprint cell towers.
(AT&T and SPRINT, has monitored a call and the "ring passthru handshake signal" is missing...but no one knows how to fix it)
I hope someone here has seen a similiar problem, and can point me in the right direction. Thanx.

 

[telcodog]

This sounds like an audio cut through issue. It probably has to do with answer supervision somewhere in your scenario. It reminds me of the old days of analog tie trunks where the talk path would not establish until the far end sent an answer signal. Given that you mention the incoming call is a DID, it wouldn't surprise me if you have to change your supervion on your outbound trunks to unsupervised (or a similar change on your DID trunks). Just a thought.

 

[MACGVEYER]

Thanx
I would like to add, that any forwarded call to a land line in the same Sprint area, behaves normally. It appears to be only when we engage the Sprint network cell phone towers, do we have this issue.
(Sprint has also monitored the call through the towers as well).
I was curious if any other Norstar MICS user has had the same issue with the Sprint towers, and what if anything they did to correct the issue.