I do notice port 7300 when the UDP packet is returned form the node IP address. I will double check if the windows firewall was on or off and test again myself to make sure. This is a log from the clients desktop for traffic between the softphone - Gateway and Sig.Server
[Sat Feb 20 11:39:44] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:44] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:44] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:44] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:44] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:44] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:44] Received UDP packet from server 172.xx.xx.xxx:5100, size 18
[Sat Feb 20 11:39:44] Received UDP packet from server 172.xx.xx.xxx:5100, size 18
[Sat Feb 20 11:39:44] Received UDP packet from server 172.xx.xx.xxx:5100, size 11
[Sat Feb 20 11:39:44] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:44] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:44] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:45] Received UDP packet from server 172.xx.xx.xxx:5100, size 35
[Sat Feb 20 11:39:45] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:45] Received UDP packet from server 172.xx.xx.xxx:5100, size 9
[Sat Feb 20 11:39:45] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:45] UDP packet sent to 172.xx.xx.xxx:5100, size 34
[Sat Feb 20 11:39:45] Received UDP packet from server 172.xx.xx.xxx:5100, size 6
[Sat Feb 20 11:39:47] Received UDP packet from server 172.xx.xx.xxx:5100, size 9
[Sat Feb 20 11:39:47] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:47] UDP packet sent to 172.xx.xx.xxx:5100, size 34
[Sat Feb 20 11:39:47] Received UDP packet from server 172.xx.xx.xxx:5100, size 6
[Sat Feb 20 11:39:49] Received UDP packet from server 172.xx.xx.xxx:5100, size 9
[Sat Feb 20 11:39:49] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:49] UDP packet sent to 172.xx.xx.xxx:5100, size 34
[Sat Feb 20 11:39:50] Received UDP packet from server 172.xx.xx.xxx:5100, size 6
[Sat Feb 20 11:39:52] Received UDP packet from server 172.xx.xx.xxx:5100, size 9
[Sat Feb 20 11:39:52] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:52] UDP packet sent to 172.xx.xx.xxx:5100, size 34
[Sat Feb 20 11:39:52] Received UDP packet from server 172.xx.xx.xxx:5100, size 6
[Sat Feb 20 11:39:54] Received UDP packet from server 172.xx.xx.xxx:5100, size 9
[Sat Feb 20 11:39:54] UDP packet sent to 172.xx.xx.xxx:5100, size 30
[Sat Feb 20 11:39:54] UDP packet sent to 172.xx.xx.xxx:5100, size 34
[Sat Feb 20 11:39:54] Received UDP packet from server 172.xx.xx.xxx:5100, size 6
[Sat Feb 20 11:40:18] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:40:19] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:40:21] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:40:22] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:40:24] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:40:25] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:40:27] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:40:28] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:40:30] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:40:47] The UDP port deleted from 192.168.1.3:8366 to 192.168.1.255:138
[Sat Feb 20 11:40:47] The UDP port deleted from 172.10.1xx.7:8364 to 172.10.1xx.255:138
[Sat Feb 20 11:40:47] The UDP port deleted from 192.168.1.4:8365 to 192.168.1.255:138
[Sat Feb 20 11:42:18] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:42:19] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:42:21] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:42:22] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:42:24] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:42:25] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:42:27] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:42:28] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:42:30] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:42:32] UDP packet sent to 172.xx.xx.xx:5100, size 33
[Sat Feb 20 11:44:18] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:44:19] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:44:21] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:44:22] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:44:24] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:44:25] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:44:27] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:44:28] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:44:30] UDP packet sent to 172.10.xx.xxx:137, size 88
[Sat Feb 20 11:44:39] The UDP port deleted from 172.1x.xx.x:8361 to 172.10.xx.xxx:4100
[Sat Feb 20 11:44:41] The UDP port deleted from 172.10.xxx.x:8362 to 172.xx.xx.xxx:7300
[Sat Feb 20 11:44:44] The UDP port deleted from 172.10.xx.x:8283 to 172.xx.xxx.xxx:10000