[Users] Bye problem

Hi Users

I'm Using the openser with Nat Bu using the RTP..

After invite method rtp is also established between the caller and callee ... Audio is clear.. But when I send Bye request to Callee , it not hung upping to callee it still estallishing the call...

I think that .... 1) openSER server is not getting the request from callee or caller 2) OPenser is respones the BYE .. 3) Router(firewall) gateways is blocking the Bye request , to pass the request to openser, 4) Route behind the UA's isbloacking....

Here I creaking and hung upping ... Plz hep this...