Port Triggering; Figure 13-11: Dmz Host - AudioCodes MP-20x User Manual

To designate a local computer as a DMZ Host:
1. From the sidebar menu, click the Security menu, and in the screen 'Security', click the
DMZ Host tab; the screen 'DMZ Host' opens.
2. Enter the local IP address of the computer to be designated as a DMZ host. Note that
only one LAN computer can be a DMZ host at any time.
3. Click OK to save your changes and return to the screen 'DMZ Host'.
You can disable the DMZ host so that it does not fully exposed to the Internet, but keep its
IP address recorded on the 'DMZ Host' screen. This may be useful if you wish to disable
the DMZ host but expect that you may want to enable it again in the future.
To disable the DMZ host so that it is not fully exposed to the Internet, clear the check-
box next to the DMZ IP designation and click OK.
To re-enable the DMZ host later, recheck the check-box.
13.5

Port Triggering

Port triggering can be used for dynamic port forwarding configuration. By setting port
triggering rules, you can allow inbound traffic to arrive at a specific LAN host, using ports
different than those used for the outbound traffic. This is called port triggering since the
outbound traffic triggers to which ports inbound traffic is directed.
For example, consider a gaming server that is accessed using UDP protocol on port 222.
The gaming server responds by connecting the user using UDP on port 333 when starting
gaming sessions. In such a case you must use port triggering, since this scenario conflicts
with the following default firewall settings:
The firewall blocks inbound traffic, by default.
The server replies to MP-20x's IP, and the connection is not sent back to your host,
since it is not part of a session.
To solve this, you need to define a Port Triggering entry, which allows inbound traffic on
UDP port 333, only after a LAN host generated traffic to UDP port 222. This results in
accepting the inbound traffic from the gaming server and sending it back to the LAN Host
which originated the outgoing traffic to UDP port 222.
MP-20x Telephone Adapter

Figure 13-11: DMZ Host

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User's Manual
Document #: LTRT-50609