Chapter 23 Voice
VMG5313-B10A/-B30A Series User’s Guide
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23.1.2 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 VMG) send messages to another. In VoIP, these messages are about phone
calls over the network. For example, when you dial a number on your VMG, 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 VMG to use your SIP account to make calls,
the VMG 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 VMG) 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 4 on page 35 for a tutorial showing how to set up these screens in an example
scenario.
See Section 23.10 on page 282 for advanced technical information on SIP.
23.2 Before You Begin
• Before you can use these screens, you need to have a VoIP account already set up. If you don’t
have one yet, you can sign up with a VoIP service provider over the Internet.
• You should have the information your VoIP service provider gave you ready, before you start to
configure the VMG.
23.3 The SIP Account Screen
The VMG uses a SIP account to make outgoing VoIP calls and check if an incoming call’s destination
number matches your SIP account’s SIP number. In order to make or receive a VoIP call, you need