40 E-DOC-CTC-20051017-0148v1.0
Chapter 4
Voice over IP
provided by your ISP:
5Click Apply.
Verifying telephone
connectivity
Proceed as follows to verify the voice connection:
1Make sure the SpeedTouch™ is turned on and ready for service.
2Check whether your phone is properly attached to the SpeedTouch™.
3Make sure the Internet telephony service is enabled and configured.
4The VoIP Ready LED must be lit.
5Pick up your phone, wait for the dialling tone, and dial the number. If you dial
a ‘#’ after the phone number, the phone number will be called instantly.
Some of the SIP components are explained below:
Proxy: The SIP proxy server at your provider’s forwards signalling
messages between the caller and callee.
Registrar: The SIP registrar resembles a DNS, as it matches your URI
with your IP address. Your SpeedTouch™ will periodically - depending
on the expire time - register its correct IP address with the SIP registrar
that may be collocated with the proxy server.
Expire Time: This is the frequency with which your IP address is
updated on the registrar.
The phone(s) attached to the SpeedTouch™ can receive incoming VoIP
calls, as long as your SpeedTouch™ is turned on and the VoIP Ready LED is
lit.
For calls over the regular phone line, your phones are line powered by the
telephone company and can therefore always be reached, even if the
modem is turned off.