ZyXEL Communications p-2612HNU-FX Manuel D’Utilisation

Chapter 9 Voice

P-2612HNU-Fx User’s Guide

The following terms and concepts may help as you read this chapter.

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 stands for Session Initiation Protocol. SIP is a signalling standard that lets one 
network device (like a computer or the ZyXEL Device) send messages to another. 
In VoIP, these messages are about phone calls over the network. For example, 
when you dial a number on your ZyXEL Device, it sends a SIP message over the 
network asking the other device (the number you dialed) to take part in the call. 

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 
ZyXEL Device to use your SIP account to make calls, the ZyXEL Device 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 ZyXEL Device) 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. 

 for a tutorial showing how to set up these screens in an 

example scenario.

 for advanced technical information on SIP.