usually in the range 192.168.x.x, 172.16.x.x or 10.x.x.x. These IP addresses are used where you have multiple computers all sharing the same Internet connection.
To access the Internet, a computer or VoIP device must have an IP address. So what do you do if your ISP (Internet Service Provider) has provided you with only 1 IP address but you have more than 1 device that requires Internet access? The solution is to give each of the devices on the LAN a Private IP Address. A router makes them work by performing Network Address Translation (NAT — See the next topic for details).
Note that addresses of the form192.168.x.x, 172.16.x.x or 10.x.x.x are not recognized on the Internet and can only be used for private networks. For example, if you tell someone on the Internet to connect to you using a 192.168.x.x address, it will not work. Instead, you must provide your real/ Public IP Address.
What is NAT and how does it affect VoIP?
Network Address Translation (NAT) allows multiple devices to share the same external IP address to access resources on the Internet. NAT is typically used to allow all the devices in a subscriber’s local area network to access the Internet through a router with a single public IP address assigned by the Internet Service Provider.
If a VoIP device is sitting behind a NAT, the private IP address assigned to it is not usable for communications with the entities outside the private network. The VoIP device must substitute the private IP address information with the proper external IP address/port in the mapping chosen by the underlying NAT to communicate with a particular public peer address/port. TalkSwitch can automatically check for the current public IP address and substitute the private IP address with the public address so that VoIP traffic is properly routed through the NAT.
What’s the difference between a Static IP Address and a Dynamic IP Address and what effect does this have on VoIP?
A Static IP Address is an address that is permanently assigned to a device. Typically, a Static IP Address has to be assigned by the network administrator or Internet Service Provider (ISP).
A Dynamic IP Address is an address that is temporarily assigned to devices by a DHCP or PPP server that maintains and assigns a pool of IP addresses.
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