Specifications

connections.IfthePBXhasonlyoneNIC,thentherewillbenoneedtosetthisfield.Inour
examplethisis192.168.9.213.
3. Set the Tunnel Listening Port to the port, which will be receiving tunnel connections. The
defaultvalueis5090.
4. Click“OK”.TheTunnelservicewillberestartedautomatically.
Step2–ConfiguretheFirewall
The Tunnel protocol is designed to eliminate NAT traversal problems and reduce Firewall
configuration work to a minimum. There is only one Firewallsetting that needs to be made – we
mustforwardtheTCPTunnelport(setbydefaultto5090)tothePBX.
ConfiguringaPortForwardRuleinpfSense
The above picture shows configuration for a pfSense firewall  most firewalls will provide similar
functionality.Inyourfirewall:
1. EnablePortForwarding.
2. SpecifythePBX’sLocalIPAddress(whichwehadsetpreviouslyto192.168.9.213)
3. SettheTypeto“TCP”.
4. SetthePortRangetobefrom5090to5090(onlyoneport).
5. SettheCommentfieldto“3CXTunnel”.
6. Clickonthe “Add”buttonfollowedby the“Apply”button.Your firewallconfigurationisnow
done!
Step3–ConfiguringRemote3CXPhones,Bridgesand3CXSBC
Afteryouhaveconfiguredthelocaltunnelconnectionandthefirewall,thetunnelisnow“readyfor
use”.The3CXTunneltechnologycanbeusedinthefollowingscenarios:
ConnectRemote3CXPhoneUsers
3CXPhone for Windows, Mac and Android have a built in tunnel that will be used automatically
when3CXPhonedetectsitisnotontheLAN.Noconfigurationisnecessaryin3CXPhone.
Inthecaseof3CXPhoneforiPhone,theTunnelappmustbedownloadedasaseparateappfrom
theAppleAppStore,asit’snotallowedtointegratethefeaturedirectlyinto3CXPhoneforiPhone.
Inthiscasetheusermustswitchonthe3CXTunnelAppwhenplacingcalls.Forfurtherinformation
about3CX Tunnel options in3CXPhone, see the chapter“Configuring the 3CX PhoneSystem
Clients–3CXPhone”.
Connect3CXPhoneSystemsviaaBridge