Switching to VoIP

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VoIP or IP Telephony

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and voice mail. These tasks are the applications of Voice over IP. Voice applications

delivered using IP datagrams is the essence of VoIP.

VoIP, like the network that carries it, is therefore not an application by itself, but a

way to build applications using myriad software tools and devices. These building

blocks can be specialized VoIP server hardware like an analog telephone adapter

(ATA), or they can be highly programmable servers that do the job of a PBX. Regard-

less, all VoIP components must participate in the protocol conversations that make

the audible, human phone conversations possible. That means that all VoIP compo-

nents must be speaking the same language.

In human conversation, people can speak many different languages. Even among dif-

ferent dialects of the same language, people can have a hard time understanding each

other—a Bostonian and a Texan sound about as different as a Canadian and an Aus-

tralian, even though they all speak English. Unfortunately, telephony standards have

had similar challenges.

Many standards govern the world of Voice over IP, and some have interoperability

problems, just as people with local accents sometimes confuse each other. One such

annoyance lies in the definition of the word VoIP itself.

VoIP or IP Telephony

Are ...