If this is any help this is the firewall checker log.
3CX Firewall Checker, v1.0. Copyright (C) 3CX Ltd. All rights reserved.
<08:58:28>: Phase 1, checking servers connection, please wait...
<08:58:29>: Stun Checker service is reachable. Phase 1 check passed.
<08:58:29>: Phase 2a, Check Port Forwarding to UDP SIP port, please wait...
<08:58:40>: UDP SIP Port is set to 5060. Response received WITH TRANSLATION 55028::5060. Phase 2a check passed with WARNINGS. Some functionality will be LIMITED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<08:58:40>: Phase 2b. Check Port Forwarding to TCP SIP port, please wait...
<08:58:45>: TCP SIP Port is set to 5060. Response received WITH TRANSLATION 55028::5060. Phase 2b check passed with WARNINGS. Some functionality will be LIMITED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<08:58:45>: Phase 3. Check Port Forwarding to TCP Tunnel port, please wait...
<08:58:50>: TCP TUNNEL Port is set to 5090. Response received WITH TRANSLATION 55064::5090. Phase 3 check passed with WARNINGS. Some functionality will be LIMITED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<08:58:50>: Phase 4. Check Port Forwarding to RTP external port range, please wait...
<08:59:13>: UDP RTP Port 9000. Response received WITH TRANSLATION 55066::9000. Phase 4-01 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<08:59:18>: UDP RTP Port 9001. Response received WITH TRANSLATION 55065::9001. Phase 4-02 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<08:59:22>: UDP RTP Port 9002. Response received WITH TRANSLATION 55068::9002. Phase 4-03 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<08:59:27>: UDP RTP Port 9003. Response received WITH TRANSLATION 55067::9003. Phase 4-04 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<08:59:31>: UDP RTP Port 9004. Response received WITH TRANSLATION 55070::9004. Phase 4-05 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<08:59:36>: UDP RTP Port 9005. Response received WITH TRANSLATION 55069::9005. Phase 4-06 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<08:59:40>: UDP RTP Port 9006. Response received WITH TRANSLATION 55072::9006. Phase 4-07 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<08:59:45>: UDP RTP Port 9007. Response received WITH TRANSLATION 55071::9007. Phase 4-08 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<08:59:49>: UDP RTP Port 9008. Response received WITH TRANSLATION 55074::9008. Phase 4-09 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<08:59:54>: UDP RTP Port 9009. Response received WITH TRANSLATION 55073::9009. Phase 4-10 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<08:59:58>: UDP RTP Port 9010. Response received WITH TRANSLATION 55076::9010. Phase 4-11 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:00:03>: UDP RTP Port 9011. Response received WITH TRANSLATION 55075::9011. Phase 4-12 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:00:07>: UDP RTP Port 9012. Response received WITH TRANSLATION 55078::9012. Phase 4-13 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:00:12>: UDP RTP Port 9013. Response received WITH TRANSLATION 55001::9013. Phase 4-14 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:00:16>: UDP RTP Port 9014. Response received WITH TRANSLATION 55080::9014. Phase 4-15 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:00:21>: UDP RTP Port 9015. Response received WITH TRANSLATION 55079::9015. Phase 4-16 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:00:25>: UDP RTP Port 9016. Response received WITH TRANSLATION 55082::9016. Phase 4-17 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:00:30>: UDP RTP Port 9017. Response received WITH TRANSLATION 55081::9017. Phase 4-18 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:00:34>: UDP RTP Port 9018. Response received WITH TRANSLATION 55084::9018. Phase 4-19 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:00:39>: UDP RTP Port 9019. Response received WITH TRANSLATION 55083::9019. Phase 4-20 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:00:43>: UDP RTP Port 9020. Response received WITH TRANSLATION 55086::9020. Phase 4-21 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:00:48>: UDP RTP Port 9021. Response received WITH TRANSLATION 55085::9021. Phase 4-22 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:00:52>: UDP RTP Port 9022. Response received WITH TRANSLATION 55088::9022. Phase 4-23 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:00:57>: UDP RTP Port 9023. Response received WITH TRANSLATION 55087::9023. Phase 4-24 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:01:01>: UDP RTP Port 9024. Response received WITH TRANSLATION 55090::9024. Phase 4-25 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:01:06>: UDP RTP Port 9025. Response received WITH TRANSLATION 55089::9025. Phase 4-26 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:01:10>: UDP RTP Port 9026. Response received WITH TRANSLATION 55092::9026. Phase 4-27 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:01:15>: UDP RTP Port 9027. Response received WITH TRANSLATION 55091::9027. Phase 4-28 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:01:19>: UDP RTP Port 9028. Response received WITH TRANSLATION 55094::9028. Phase 4-29 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:01:24>: UDP RTP Port 9029. Response received WITH TRANSLATION 55093::9029. Phase 4-30 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:01:28>: UDP RTP Port 9030. Response received WITH TRANSLATION 55096::9030. Phase 4-31 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:01:33>: UDP RTP Port 9031. Response received WITH TRANSLATION 55095::9031. Phase 4-32 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:01:37>: UDP RTP Port 9032. Response received WITH TRANSLATION 55098::9032. Phase 4-33 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:01:42>: UDP RTP Port 9033. Response received WITH TRANSLATION 55097::9033. Phase 4-34 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:01:46>: UDP RTP Port 9034. Response received WITH TRANSLATION 55100::9034. Phase 4-35 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:01:51>: UDP RTP Port 9035. Response received WITH TRANSLATION 55099::9035. Phase 4-36 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:01:55>: UDP RTP Port 9036. Response received WITH TRANSLATION 55102::9036. Phase 4-37 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:02:00>: UDP RTP Port 9037. Response received WITH TRANSLATION 55101::9037. Phase 4-38 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:02:04>: UDP RTP Port 9038. Response received WITH TRANSLATION 55104::9038. Phase 4-39 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:02:09>: UDP RTP Port 9039. Response received WITH TRANSLATION 55103::9039. Phase 4-40 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:02:13>: UDP RTP Port 9040. Response received WITH TRANSLATION 55106::9040. Phase 4-41 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:02:18>: UDP RTP Port 9041. Response received WITH TRANSLATION 55105::9041. Phase 4-42 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:02:22>: UDP RTP Port 9042. Response received WITH TRANSLATION 55108::9042. Phase 4-43 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:02:27>: UDP RTP Port 9043. Response received WITH TRANSLATION 55107::9043. Phase 4-44 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:02:31>: UDP RTP Port 9044. Response received WITH TRANSLATION 55110::9044. Phase 4-45 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:02:36>: UDP RTP Port 9045. Response received WITH TRANSLATION 55109::9045. Phase 4-46 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:02:40>: UDP RTP Port 9046. Response received WITH TRANSLATION 55016::9046. Phase 4-47 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:02:45>: UDP RTP Port 9047. Response received WITH TRANSLATION 55111::9047. Phase 4-48 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:02:49>: UDP RTP Port 9048. Response received WITH TRANSLATION 55112::9048. Phase 4-49 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
<09:02:54>: UDP RTP Port 9049. Response received WITH TRANSLATION 55113::9049. Phase 4-50 check passed with WARNINGS. Some functionality may be IMPAIRED. For more information, please visit http://www.3cx.com/support/firewall-checker.html
Application exit code is 53