Cannot make Outgoing Calls

How do I fix or make work. I wonder why it works with one SIP provider but not another.

How should I work to resolve.

Do you have another router to try? Have you tried hard forwarding SIP (UDP 5060) and UDP RTP (whatever you have in etc/asterisk/rtp.conf)?

I have port forwarding set for UDP 5060 to my freepbx machine, and ports 10000-20000 to UDP to my freepbx machine. Everything works great with my SIP provider Flowroute, its my provider E4SIP that it wont reach on outgoing. Incoming is fine. I don’t get what I am missing. I tried changing the setting to UDP and RTP on both with no change as well. I do have a ATT micro cell with ports so I can boost my cell phone signal but those ports are not close to the Freepbx ports. I even tried putting the asterisk in a DMZ outside firewall that didn’t seem to work. It only fails when making outgoing calls. It also fails on my polycom, linksys pap, and Linksys phone so it must be some setting with the other provider. I don’t have the issue with flowroute at all which seems very strange. My provider doesn’t get it either. At first they thought it might be that I had IPV6 turned on which I terminated, but my router supports IPV6 as well. I can’t change my router since its from Comcast and it controls the complete wireless and internet connection. I guess I could buy a new cable modem, but wanted to see if it was a setting thing. Following are the port open settings I currently am using:
3G UDP 123 123 10.0.0.2 EDIT X
3G 1 TCP 443 443 10.0.0.2 EDIT X
3G 2 UDP 4500 4500 10.0.0.2 EDIT X
3G 3 UDP 500 500 10.0.0.2 EDIT X
PBX UDP 5060 5060 10.0.0.10 EDIT X
PBX2 TCP/UDP 10000 20000 10.0.0.10

I appreciate your assistance.

Does anyone have suggestions as to why I still am getting router issues? Any ideas on how to fix?

Is there a configuration I am missing? I believe I have all the necessary ports open just not sure why I can not connect to the one SIP provider.

Please try and provide assistance. I could try and buy a new modem and router as well. Any suggestions?

i followed the instructions on the page below:
http://www.freepbx.org/support/documentation/howtos/howto-setup-a-remote-sip-extension

outside local network, i was able to make sip calls inbound but on outbound i am receiving the sip extension is not available.

NAT = yes
IP Configuration = Dynamic IP
Dynamic Host = website.dyndns.org refresh rate = 120
Local Networks = 192.168.1.0 / 255.255.255.0

please refer to link below this might help. (Spanish version need google translate)

http://www.elastix.org/index.php/es/component/kunena/11-ayuda/97861-sin-audio-extensiones-remotas.html

let me know the results.
credits to Claudio of Elastix