Dismiss Notice
We would like to remind you that we’re updating our login process for all 3CX forums whereby you will be able to login with the same credentials you use for the Partner or Customer Portal. Click here to read more.

Firewall ports opening

Discussion in '3CX Phone System - General' started by Mike99, Sep 13, 2017.

Thread Status:
Not open for further replies.
  1. Mike99

    Aug 25, 2017
    Likes Received:
    We are in the phase of migrating from cisco CME to 3CX. For security reasons the 3CX PBX is in a DMZ network and connects to the current CME via generic SIP trunk. The phones are also on the local LAN and pass through the firewall to reach the 3CX PBX. We used this document for ports opening but things didn't turn up right (https://www.3cx.com/docs/manual/firewall-router-configuration/)

    - the SIP trunk between the 3CX PBX and CME was working unidirectional for calls signaling and there was no audio
    - in general the system was not working well
    - everything worked well when the firewall was removed

    Questions :
    - Are there other ports that should be opened to allow phones and CME from the internal network to work fine with the 3CX in the DMZ ?
    - Is there a best practise design guide for the future when we'll have an external SIP trunk ? Where should one place the 3CX PBX ? DMZ or its advised to have it on the internal network together with the phones ?
    - Is the port opening unidirectional or bidirectional ? According to the document , it seems to be unidirectional.
    - Nat : Should we nat all traffic to the 3CX PBX ?

    Thanks in advance
  2. V..


    Feb 14, 2017
    Likes Received:
    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
    #2 V.., Sep 13, 2017
    Last edited by a moderator: Aug 29, 2018
Thread Status:
Not open for further replies.