My PBX server is working fine behind GW1 but when I changed it to GW2 all the trunks are down however we are using the same rule as per GW1.
When I do nmap for port checking port is up. nmap -v -sU -p 5060 x.x.x.x
Starting Nmap 5.51 ( http://nmap.org ) at 2017-10-25 14:35 EDT
Initiating Ping Scan at 14:35
Scanning x.x.x.x [4 ports]
Completed Ping Scan at 14:35, 0.31s elapsed (1 total hosts)
Initiating Parallel DNS resolution of 1 host. at 14:35
Completed Parallel DNS resolution of 1 host. at 14:35, 0.17s elapsed
Initiating UDP Scan at 14:35
Scanning x.x.x.x [1 port]
Completed UDP Scan at 14:35, 3.05s elapsed (1 total ports)
Nmap scan report for x.x.x.x
Host is up (0.30s latency).
PORT STATE SERVICE
5060/udp open|filtered sip
Read data files from: /usr/share/nmap
Nmap done: 1 IP address (1 host up) scanned in 3.61 seconds
Raw packets sent: 6 (208B) | Rcvd: 3 (154B)