Switching to VoIP

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Distributed Versus Mainframe

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When the receiving phone rings, have somebody answer the call. If you can hear the

other person talk through your IP phone’s handset, you’ve just made your first suc-

cessful VoIP phone call—sort of the IP equivalent of Bell’s and Watson’s first phone

call back in 1876.

If the receiving phone doesn’t ring, then you should check the IP address you dialed,

check the phone’s configuration to make sure it is listening on the default port for

SIP (5060), and make sure SIP registration is turned off. These options, which are

accessed in the Budgetone’s web configuration page, will be covered in greater detail

later.

Dialing by IP address isn’t user-friendly, and it isn’t practical at all in a

DHCP environment, let alone an enterprise or home phone system.

Outside your test lab, you’ll use it only for troubleshooting.

Distributed Versus Mainframe

In the world of traditional telephony, endpoints and PBXs interact in a manner simi-

lar to dumb terminals and mainframe computers. That is, the PBX (or mainframe)

has all of the application functionality built in, and the user interface functions of the

endpoints (or terminals) are dictated by the PBX.

With IP telephony, voice endpoints are far more programmable, lessening the

requirement for centralization. VoIP endpoints ...