Telephony Technology
PSTN & VoIP
PSTN
Public Switched
Telephone Network
Figure 1. The PSTN architecture.
VoIP
Voice over Internet
Protocol
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H.323
SIP
RTP
SDP
IAX
SRTP
Skype
And a lot more…
VoIP
PSTN
Voice over Internet
Protocol
VoIP Server
Figure 2. The VoIP architecture.
Application
Asterisk & WebRTC
Asterisk
Asterisk is a flexible and extensible
suite of integrated
telecommunications software.
Asterisk
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Asterisk designed to support many
telephony technologies
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It powers IP PBX systems, VoIP
gateways, conference servers
The Asterisk application runs under
the Linux operating system
Asterisk
WebRTC
Web Real Time
Communication
WebRTC
WebRTC is a open project
that enables web browsers with
Real-Time Communications
capabilities
via simple Javascript APIs.
WebRTC
Supported Browsers
WebRTC
CU-RTC-Web
WebRTC
Customizable, Ubiquitous
Real Time Communication
over the Web
WebRTC
• MediaStream : get access to data streams, such as from the
user's camera and microphone.
• RTCPeerConnection : audio or video calling, with facilities for
encryption and bandwidth management.
• RTCDataChannel : peer-to-peer communication of generic
data.
WebRTC
The offer/answer architecture is called
JSEP
JavaScript Session Establishment Protocol
Figure 3. The JSEP architecture.
System Design
SIP Clients
SIP Clients
Asterisk
WebRTC Clients
PSTN
System Design
System Design