Hello everyone, I'm going crazy with my current issue and need some advice from someone who knows 3cx Session border controllers and pfSense. I have taken over the IT work for 3 sites for the same company: -1 site with 3CX loaded on the file server and behind an Untangle firewall (let's call it Site Home) -1 site with a Session Border Controller behind an Untangle firewall (Site A) -1 site with an SBC behind a pfSense firewall (Site B) All 3 sites have ports 5060 and 5090 (TCP/UDP) forwarded to the SBC and PBX for each site Site Home can communicate with Site A without issue. All Yealink T46Gs run without issue Site Home cannot communicate with Site B. Site B's Yealink T46G phone says "Register failed" everytime it tries to register with the SBC and PBX. The SBC at Site B gives the following error: "ALERT | 20170420-183017.347 | 3CXTunnel | TUNL | 1995964416 | /home/repomaster/root15/Sources/Projects/3CXSBC/TunnelTcp.cpp:660 | Sending first packet from [ V4 0.0.0.0:42808 UNKNOWN_TRANSPORT ] to [ V4 [PBX PUBLIC ADDRESS]:5090 TCP ]ERR | 20170420-183019.373 | 3CXTunnel | TUNL | 1995964416 | /home/repomaster/root15/Sources/Projects/3CXSBC/TunnelTcp.cpp:262 | Bridge [sbc07co] failure 'Connection is terminated by peer - while begin to read a packet from tunnel' on TCP connection: TunnelTcp:rocess" All SBC are running the version from 1/18/2017 The PBX is running v14 SP2 Yealink phones are running firmware v18.104.22.168 I feel like I'm missing something, but right now I can't tell the forest from the trees.