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Figure 33.1 |
Conceptual organization of the most basic IP telephone system.
An IP telephone uses the controller to find another IP telephone and
establish a call.
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Figure 33.2 |
The interconnection of an IP telephone system with the Public
Switched Telephone Network. Gateways handle both voice and signaling.
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Figure 33.3 |
The set of protocols various groups have proposed for use with
IP telephony and the layer at which each operates.
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Figure 33.4 |
The layering of some of the protocols that comprise the H.323 standard.
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Figure 33.5 |
The six basic SIP methods.
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