Snom ONE IP, Техническое руководство

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Chapter
1
GETTING STARTED
W
elcome to snom ONE, your state-of-the-art IP telephone system. Administrating a
VoIP system can be a daunting task for administrators unfamiliar with VoIP. This guide
is designed to help you plan and configure snom ONE Voice over IP (VoIP) deploy-
ments ranging in complexity from a small office using the Internet for SIP trunks to a
large, multi-national conglomerate of snom ONE systems.
snom ONE is the answer to all your IP telephone system needs.
About snom ONE
snom ONE is a SIP-based IP telephone system which is implemented in a back-to-
back user agent (or B2BUA), so all traffic between two endpoints traverses the system
(Figure 1-1). This gives the system complete control of the call state and allows it to
participate in all call requests. It also allows it to perform a number of functions that
are impossible using the SIP proxy model. A few such functions are forking calls to the
cell phone, returning them to the system, if needed, and connecting phones remotely to
the system. The B2BUA also facilitates advanced media features such as call recording,
barge, listen in, and whisper, as well as ensuring two-way audio session is established.
Answering
SIP UA
Originating
SIP UA
Originating
SIP Endpoint
Answering
SIP Endpoint
Figure 1-1. B2BUA Architecture