Bizfon 2000 Guida All'Installazione

Pagina di 44
Bizfon Manual I: Installation Guide 
Appendix: Configuring NAT Traversal 
 
Appendix: Configuring NAT Traversal 
NAT or Network Address Translation is a common feature used to expand the use of con-
nected PCs and other networked devices without having to use multiple global Internet 
public IP addresses. Most ISP’s will assign one public IP address to each customer that is 
connected to the Internet. The customer can use a router to provide NAT capability and 
create a private network of PCs and other devices not visible from the Internet. This 
method offers security and also eliminates the need to assign global Internet public IP ad-
dresses to each device on the LAN. 
The Bizfon initiates and receives SIP calls from the Internet (or the network connected to 
the WAN port). To receive SIP calls, the Bizfon must be able to receive packets from the 
SIP server or any other device that is trying to make an incoming call. If the Bizfon is placed 
behind a router with NAT, like most basic routers on the market today, the Bizfon will not be 
able to receive calls. To resolve this issue, either STUN must be enabled on the Bizfon or 
SIP NAT traversal must be set up in the router and in the Bizfon to route the incoming calls 
properly. 
Please Note:
 NAT traversal only works with Internet connections that have static IP ad-
dresses. Verify from your provider that this is the case for your Internet connection. Some 
ISPs provide dynamic IP addresses that may change from time to time, and are not appro-
priate for SIP NAT traversal.  
Please Note:
 If you have more than one router in series between the Bizfon and the Inter-
net, the same port forwarding setup must be configured on each router. 
NAT Traversal Setup 
• 
Install the Bizfon behind the router. If the Bizfon is configured with its factory default 
settings, it is already configured for DHCP and will obtain an IP address automatically 
from the router.  
• 
Connect a PC to the Bizfon LAN port and power it up. 
• 
Verify the Bizfon can connect to the Internet by opening a browser window and brows-
ing to a familiar WEB site. If the Bizfon cannot reach the Internet, verify the LAN/WAN 
LEDs and the cabling. Verify the Bizfon is set up for DHCP on the WAN and that the 
router has the DHCP server enabled for the devices behind it. 
• 
Find the address of the router and log into the router. Refer to the router’s user manual 
 IP address. Your router also may indicate the IP address assigned to the 
yip.com
on how to open the router configuration. 
 
Set up port forwarding on the router to forward UDP ports 5060, 6000-6099 to the IP 
address assigned to the Bizfon. You can see the IP address of the Bizfon in the Sys-
tem  
menu under Status, submenu Network Status. The IP address will be listed as 
the WAN
Bizfon. 
 
Find out the public Internet address (WAN IP address) of the router. To do so, open a 
browser and go to 
. The site will return your public Internet IP ad-
e enable NAT Traversal for SIP radio 
buttons selection to ForceSave the selection. 
 
dress. Record this IP address. 
 
 
From the Telephony menu of the Bizfon Management go to the NAT Traversal Set-
tings
 page, go to General Settings and set th
 
Bizfon2000 and Bizfon4000; (SW Version 4.1.x)
 
39