What You Need To Know About Voip - ZyXEL Communications P-2812HNU-51c User Manual

Chapter 9 Voice
You don't necessarily need to use all these screens to set up your account. In fact,
if your service provider did not supply information on a particular field in a screen,
it is usually best to leave it at its default setting.

9.1.2 What You Need to Know About VoIP

VoIP
VoIP stands for Voice over IP. IP is the Internet Protocol, which is the message-
carrying standard the Internet runs on. So, Voice over IP is the sending of voice
signals (speech) over the Internet (or another network that uses the Internet
Protocol).
SIP
SIP stands for Session Initiation Protocol. SIP is a signalling standard that lets one
network device (like a computer or the P-2812HNU-51c) send messages to
another. In VoIP, these messages are about phone calls over the network. For
example, when you dial a number on your P-2812HNU-51c, it sends a SIP
message over the network asking the other device (the number you dialed) to
take part in the call.
SIP Accounts
A SIP account is a type of VoIP account. It is an arrangement with a service
provider that lets you make phone calls over the Internet. When you set the P-
2812HNU-51c to use your SIP account to make calls, the P-2812HNU-51c is able
to send all the information about the phone call to your service provider on the
Internet.
Strictly speaking, you don't need a SIP account. It is possible for one SIP device
(like the P-2812HNU-51c) to call another without involving a SIP service provider.
However, the networking difficulties involved in doing this make it tremendously
impractical under normal circumstances. Your SIP account provider removes these
difficulties by taking care of the call routing and setup - figuring out how to get
your call to the right place in a way that you and the other person can talk to one
another.
How to Find Out More
See Chapter 2 on page 29
example scenario.
See Section 9.9 on page 188
172
for a tutorial showing how to set up these screens in an
for advanced technical information on SIP.
P-2812HNU-51c User's Guide