What Is A Vpn? Can A Vpn Help Me To Carry Data Securely Over The Internet; What's The Difference Between A Public Ip Address And A Private Ip Address - Talkswitch 48-CA User Manual

Over the last couple of years, the Voice over IP community has adopted SIP as its
protocol of choice for signalling. SIP is an RFC standard (RFC 3261) from the Internet
Engineering Task Force (IETF), the body responsible for administering and developing
the mechanisms that comprise the Internet.
The IETF's philosophy is one of simplicity: specify only what you need to specify. SIP is
very much of this mould; it just initiates, terminates and modifies sessions. This
simplicity means that SIP scales, it is extensible, and it sits comfortably in different
architectures and deployment scenarios.

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

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. A VPN provides
security by using encryption/decryption. Using a process called 'tunneling', private
data is encrypted and then encapsulated before being sent across the network. These
packets of information are sent to their destination. Only those with the correct
protocol information are able to enter a company's network.
A VPN is very useful for providing employees with remote access to the company
network without compromising security. Encryption can have a negative impact on the
call quality, as the overhead on the network connection is increased. For example,
IPSec adds approximately 10 per cent 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, then you must tell
them your public address. Also known as your "real" or "external" address.
Private IP Addresses are typically assigned to devices on a LAN (Local Area Network)
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 typically 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.
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