Asterisk Calls cuts of at 32nd second.

We have Class5 soft Switch (Voipswitch) And this switch send calls to asterisk and asterisk makes some changes to CLI prefix etc. and send it to Termination Partner. We can make calls from IOS app. and Access number. there is no issue. But if we call from Android app the call cuts of at 32nd second. There is no issue the calls from IOS and Access number. We need to fix this problem ASAP. Only VOIP and asterisk experts please.