Hi to all. I have a issue with my sip phone (grandstream budget tone 100), I'm trying to config as a extenal extension in other home, it pass under a router and the port 5060 is NATed now. the thing here than when i make a call from the external extension to other extension or to a land line it works perfect, but when is incoming call, it only rings but it but the phone not connect the call (it does not hang up) explaining better: calling from external extension to pbx lan extension = ok calling from pbx lan extension to external extension = rings but not hang up (the lan extensions continue say is ringing) calling from external extension to land line = works ok, 2 way audio, music on hold and transfer works. calling from land line to (routing) external extension = rings but no hang up (the land line sounds as ringing) this is the last log: NOTE: 18.104.22.168 = ip of my extenal extension, 22.214.171.124 is my pbx ip and 126.96.36.199 is (I think) voip provider Code: 21:00:15.688 [CM503003]: Call(122): Call to sip:email@example.com has failed; Cause: 408 Request Timeout; internal 21:00:13.634 Currently active calls [none] 21:00:00.534 [MS105000] C:121.1: No RTP packets were received:remoteAddr=188.8.131.52:61026,extAddr=0.0.0.0:0,localAddr=184.108.40.206:9036 20:59:59.664 [CM503008]: Call(122): Call is terminated 20:59:59.082 [CM503008]: Call(121): Call is terminated 20:59:43.582 [CM503025]: Call(122): Calling Ext:Ext.1003@[Dev:sip:firstname.lastname@example.org:5060] 20:59:43.580 [MS210002] C:122.2:Offer provided. Connection(transcoding mode): 220.127.116.11:9042(9043) any suggestion?