Talkswitch 24-CA manual What is a VPN?, Can a VPN help to carry data securely over the Internet?

The IETF’s philosophy is simplicity: specify only what you need to specify. IP just initiates, terminates and modifies sessions. In this guide, the term IP is often used in place of VoIP.

TalkSwitch phone systems use the Appello® SIP Stack for VoIP communications. The Appello® SIP Stack was developed by TalkSwitch, a division of Centrepoint Technologies Inc.

What is a VPN?

VPN stands for Virtual Private Network. It is a means of having the advantages of a private network on a shared public infrastructure like the Internet.

Can a VPN help to carry data securely over the Internet?

A VPN provides security by using encryption/decryption. Using a process called tunneling, private data is encrypted and encapsulated before being sent across the network. The packets of information are sent to their destination. Only the ones with the correct protocol information can enter a company’s network.

A VPN is most useful for providing employees with remote access to the company network without compromising security. Encryption can have a negative impact on the call quality because of the increased overhead on the network connection. IPSec adds approximately 10% overhead to VPN traffic.

What’s the difference between a public IP address and a private IP address?

A public IP address is a globally unique number that identifies a device on the Internet. If you want someone on the Internet to connect to you, they must know your public address. Also known as your real or external address.

Private IP addresses are typically assigned to devices on a Local Area Network (LAN) and are not routable outside the LAN. Private IP addresses are 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 one IP address but you have more than one 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).

Addresses of the form 192.168.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

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