Elabor par: triki mouhamed amine shili mouamed saif
Anas BADRIFiras AYADIMohamed DAHASOutlineIntroduction1)Definitions2)Services3)Architectures4) Data Transferring5)VoIP types6)Streaming types7)VoIP/Streaming protocolsConclusion
VOIP and Streaming are a techniques for transferring data .
Data could be audio for VoIP, audio and video for Streaming
Definitions3Definitions 1/2Voip (voice over IP): A new telecommunication technology that has transformed the concept of phone call.
allows to transmit voice conversations over a network via Internet Protocol (IP ).
Provides services and functions in the telephony domain.
4Definitions 2/2 Streaming :
Streaming is a technique for transferring data through internet in real time.
Streaming is a technical re-ordering of data that makes it possible for a user to view and interact with media information without having to wait for it to download entirely to his or her computer.
IP fax machine
Services 1/27Streaming services: Videoconferencing
Analog Voice (Audio SIGNAL)
Digital Voice (DATA)
Transmission over IP network
Digital Voice (DATA)
Analog Voice (Audio SIGNAL)
callerreceiverVoIP Architecture 10This is Voice Call process in VoIP :The analog voice from the caller will be transformed on a digital voice ( from audio signal to data )This data will be transmitted over the IP network.When data arrives to the receiver it has to be convert again on an audio signal to be understood.
Architecture 2/2UnicastMulticastStreaming Architecture 11Each client gets a separate stream and only if they request itdelivery of Datato a group of destination computers in a single transmission from the sourceWe can define two types of streaming media architecture: Unicast, multicats:* Unicast streaming is a 1 to 1 connection between a server and a client, meaning each client gets a separate stream and only if they request it. Unicast streaming works either for live streaming or on demand streaming.* Multicast streaming is the opposite technology for delivering datas to more than one sources at the same time, creating copies only when the links to the multiple destinations split.Multicast is most of the time used in Internet TV solutions
12Data Transferring12Data Transferring 1/213Voip and Streaming have almost the same way of work
Compression: voice and video is compressed typically with the codec
Encapsulation: the digitized voice and video is wrapped in an IP packets
3. Routing: the packets is routed thru the network to its final destination
Data Transferring2/2 Packet Switching System
The computer from which data is sent chops the data into small packets with fixing an address on each one detailing the network device where to send them.
Each packet contains a payload (like music, voice...)
All the packets traverse different paths to get to the computer.
The computer then resembles the data to their original form using the instructions contained in the packets.
14Methode to transfare data15VoIP types15VOIP types 1/316ATA (Analog Telephone Adaptor)
The ATA is an analog-to-digital converter.
This device allows one to connect a standard phone to the computer and the internet connection for using VoIP.
What the ATA device does is that it takes the analog signal from the phone and converts it into digital data. This digital data can then be transmitted over the internet.
VOIP types 2/317IP Phones
This phone is connected directly into the router.
IP phones have all the hardware and software that are necessary to handle the IP call.
VOIP types 3/318 PC-To-PC
This is the easiest way to use VoIP. It is also very inexpensive.
The basic requirements are software, a microphone, speakers, a sound card, and a fast internet connection.
Streaming types19Real Streaming
Requires a special server (a streaming server) which broadcasts the audio/video information in real time.
The player on the visitor's computer interprets this stream of data and visualizes it immediately.
Requires powerful servers (needs a lot of resources)
Streaming types 1/220Dont need a lot of resources(standard web server).
Playing part of the downloaded video, file while the rest of the file is still being downloaded.
Modern Flash, QuickTime and RealMedia players combined with a fast server, however, manage to play such videos without many problems and to minimize the buffering time.
Streaming types 2/2Pseudo Streaming (HTTP streaming )21
22Voip/Streaming protocols22Voip/Streaming protocols 1/423Codec Protocol :
Codecs are used to convert an analog voice signal to digitally encoded version.
Codecs vary by the sound quality, the bandwidth required, the computational requirements. SIP protocol TheSession Initiation Protocolis a signaling communicationprotocol
Functionalities: INVITES:allowstheapplicationof a newsessionACK:confirmsthe establishment oftheINVITEBYE: terminatesthesessionCANCEL:cancelsthesession establishment
Voip/Streaming protocols 2/424RTP (real time protocol) transport layer:
RTP supplies necessary tools for the applications: sequencing and timestamp
RTP reconstitutes the order of packages, synchronizes media and detect the loss of packages
Voip/Streaming protocols 3/425RTSP: Real time streaming protocol (transport layer)It supports the following operations:retrieval the media from a serverinvitation of a media server to a conferencerecording of a conference Its Major methodsSETUP: server allocates resources for a stream and starts an RTSP sessionPLAY: starts data on a streamPAUSE: temporarily halts a streamTEARDOWN: free resources of the stream, no RTSP session on server any more
Voip/Streaming protocols 4/426Conclusion27VoIP and streaming technologies will be the trend of futureThe market for VoIP applications and streaming media for manufacturers is growing exponentially