Voice over IP

    SIP v2 (RFC 3261)/SDP (RFC2327/3264)
    RTP/RTCP (RFC1890)
    Codec: G.711, G.729a/b, G.722
    G.168 echo cancellation
    VAD/CNG
    Dynamic jitter buffer
    DTMF
    T.38 FAX relay
    Call Waiting/Transfer/Forward/Hold/Retrieve/Block
    Three way conference
    CLIP/CLIR

16.1  Overview
Use this chapter to:
•  Connect an analog phone to the Device.
•  Make phone calls over the Internet, as well as the regular phone network.
•  Configure settings such as speed dial.
•  Configure network settings to optimize the voice quality of your phone calls.

16.1.1  What You Can Do in this Chapter
These screens allow you to configure your Device to make phone calls over the Internet and your regular phone line, and to set up the phones you connect to the Device.
•  Use the SIP Service Provider screen to configure the SIP server information, QoS for VoIP calls, the numbers for certain phone functions (Section 16.3 on page 224). 
•  Use the SIP Account screen to set up information about your SIP account, control which SIP accounts the phones connected to the Device use and configure audio settings such as volume levels for the phones connected to the ZyXEL Device (Section 16.3 on page 224).
•  Use the Common screen to configure RFC3262 support on the Device (Section 16.5 on page 228).
•  Use the Phone Device screen to control which SIP accounts the phones connected to the Device use (Section 16.6 on page 229).
•  Use the Region screen to change settings that depend on the country you are in (Section 16.7 on page 231).
•  Use the Call Rule screen to set up shortcuts for dialing frequently-used (VoIP) phone numbers (Section 16.8 on page 231).
•  Use the FXO  screen to set up the PSTN line used to make regular phone calls which do not use the Internet (Section 16.9 on page 233). 

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.