Note

SIP is the most popular Voice over IP (VoIP) standard. SIP enables two or more people to make phone calls to each other using the Internet to carry the call.

By using the Internet, you gain some distinct advantages over traditional telephone calls or PSTN (Public Switched Telephone Network):

• Call quality: SIP calls on broadband are digital quality calls across the street or across the globe.
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• Cost: SIP to SIP calls are always free and calls to old PSTN phones are very inexpensive with no taxes or monthly fees.
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• Features: Because SIP calls are part of the Internet you get great features like free voicemail to email and phone numbers from many places in the world no matter where you live.

BEST FREE SIP PROVIDERS ARE:

Gizmo.com and Tpad.com

Required Equipment:

1) IP phone or

2) ATA Adaptor

3) ADSL Connection  at both ends.