User`s guide

Allworx Server Administrator’s Guide Version 7.6
Page 144 1-866-ALLWORX * 585-421-3850
www.allworx.com
Revised: 11/22/13
Allworx PX 6/2 Expander, enter Config Mode. See the Allworx PX 6/2 Expander
Installation Guide for more information.
17.1 Phone or Port Expander behind a Third-
Party Firewall
Remote phones and port expanders usually work well, even if they are behind a firewall.
There are several exceptions, each of which requires additional configuration steps.
Avoid most problems with firewalls by routing remote audio traffic through the server. By
default, all audio traffic from remote phones and port expanders runs through the Allworx
server. Although this avoids problems, it uses network connection bandwidth to the
server. When calls to and from remote devices go out over SIP trunks or over the
Internet to other remote devices, the bandwidth usage is 180 Kbytes per call, double that
of a regular incoming call.
This traffic can degrade the audio quality of calls that use the Internet. However, there is
a server setting that reduces the effect by enabling audio between devices to go directly
from one to the other, rather than through the server. On the Allworx server admin page,
navigate to Servers > VoIP page. Locate the Force Remote Phone audio through server
line. Click the modify link to change the setting. Disabling it reduces server bandwidth
usage. However, if doing this and the phone or port expander is behind a firewall, the
firewall requires configuration.
17.2 Difficulty Connecting Calls
If the remote device does not register with the server or if calls to and from the server
cannot be connected, change settings on the firewall and the phone or port expander to
enable communications.
To change the network settings on a handset (using soft keys) or port expander:
1. Log in to the Allworx server admin page, navigate to Config > Network Settings
menu for phones, and locate the Config Mode page for port expanders.
2. Change the following settings:
• DHCP – Disabled
• Remote Plug ‘n’ Play key – Set according to the procedure in “Phone or Port
Expander behind a Third-Party Firewall” on page 144.