Internet Communications Using SIP : Delivering VoIP and Multimedia Services With Session Initiation Protocol {2Nd Ed.}

(Steven Felgate) #1
■■ Service controller for delivery of services in conjunction with special-
ized communication servers, as will be shown in the following exam-
ples. The service controller uses SIP third-party call control [4] to
orchestrate the interaction between the various servers.
■■ Voice portal using VoiceXML [5] technology for voice control and voice
browsing. This also acts as an interactive voice-response (IVR) server.
■■ Web server for provisioning and control by end users.
■■ Presence server.
■■ Text-to-speech server.
■■ Voice-recognition server.
■■ Universal messaging (UM) server.
■■ Conference scheduler.
■■ Media mixer for audio conferences.
■■ Content server for streaming multimedia, such as stored presentations,
shows, and so on.
In addition to servers for communications, other servers round out the port-
folio:
■■ Transaction server for credit card transactions.
■■ Application service providers such as productivity software. This
allows for the integration of office applications (document editors,
spreadsheets, presentations, databases) and personal information man-
agers with real-time communications.
Really interesting applications for outsourcing, however, go beyond the
generic services shown here:
■■ Services of general interest such as travel and weather
■■ Highly specialized services such as security by voice recognition or
Public Key Infrastructure (PKI) systems
■■ Virtual communities for business and nonprofit organizations

Service providers offering such an open and integrated environment for
Web, e-mail, and voice also can be referred to as application infrastructure ser-
vice providers.
How does it work? Users can provide inputs to the service controller either
via the Web servers, the Dual-Tone Multi-Frequency (DTMF) digit collector, or
the voice portal using speech recognition with VoiceXML, or simply DTMF
input. This allows invoking services using a wide variety of devices, ranging
from plain PSTN phones to PCs and palm computers. The user input can be
either by voice channels or by using Web pages.

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