Port Forwarding - AudioCodes MP-20x User Manual

13.3

Port Forwarding

By default, MP-20x blocks all external users from connecting to or communicating with your
network. Therefore, the system is safe from hackers who may try to intrude on the network
and damage it. However, you may want to expose your network to the Internet in certain
limited and controlled ways to enable some applications to work from the LAN (game, voice
and chat applications, for example) and to enable Internet access to servers in the home
network. The Port Forwarding feature supports both of these functionalities.
The 'Port Forwarding' screen lets you define the applications that require special handling
by MP-20x. You must select the application's protocol and the local IP address of the
computer using or providing the service. If required, you can add new protocols in addition
to the most common ones provided by MP-20x.
For example, to use an FTP application on one of your PCs, select 'FTP' from the list and
enter the local IP address or host name of the designated computer; all FTP-related data
arriving at MP-20x from the Internet is then forwarded to the specified computer.
Similarly, to grant Internet users access to servers inside your home network, you must
identify each service that you want to provide and the PC that provides it. For example, to
host a Web server inside the home network you must select 'HTTP' from the list of
protocols and enter the local IP address or host name of the computer that hosts the Web
server. When an Internet user points her browser to the external IP address of MP-20x, it
forwards the incoming HTTP request to the computer that is hosting the Web server.
Additionally, port forwarding enables you to redirect traffic to a different port instead of the
one to which it was designated. If for example you have a Web server running on your PC
on port 8080 and you want to grant access to this server to anyone who accesses MP-20x
via HTTP, do the following:
Define a port forwarding rule for the HTTP service, with the PC's IP or host name.
Specify 8080 in the field 'Forward to Port'.
All incoming HTTP traffic is now forwarded to the PC running the Web server on port 8080.
When setting a port forwarding service, you must ensure that the port is not already in use
by another application, which may stop functioning. A common example is when using SIP
signaling in Voice over IP - the port used by MP-20x's VoIP application (5060) is the same
port on which port forwarding is set for LAN SIP agents.
Note:
Some applications, such as FTP, TFTP, PPTP and H323, require the support
of special specific Application Level Gateway (ALG) modules in order to work
inside the home network. Data packets associated with these applications
contain information that allows them to be routed correctly. An ALG is needed
to handle these packets and ensure that they reach their intended
destinations. OpenRG is equipped with a robust list of ALG modules in order to
enable
The ALG is automatically assigned based on the destination port.
MP-20x Telephone Adapter
maximum functionality
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User's Manual
in the home
Document #: LTRT-50609
network.