VOIP : Voice on IP ALMORI Fabien master2 ISTRe

Table of context VOIP stakes VOIP structure Protocol H.323 Advantages and drawbacks Conclusion

VOIP stakes Price reductions Triple play network PABX distributed or centralized Telephony IP Video services integrated

VOIP structure There are computer and phone on the router Possibility to phone an analogical phone One interface for the different devices of telecommunication

Protocol H.323 OSI model In the Application layer: A function for audio signal A function for video signal In the Transport layer: RAS : for the establishment of call H.245 : for a call with an analogical device H.245 : for to use the good codec. For example: a video call

Protocol H.323 (in theory) Establishment of call Réservation of the bandwidth with the protocol RSVP (Ressource reSerVation Protocol) Establishment of the audio and video communication Liberation of call

Example with the protocol

Advantages and drawbacks Standard codec Interoperability Independence with the network Independence with platforms and applications Support multi-points Management of bandwith Problem of QoS Complexy protocol Problem with the different networks

Conclusion The VOIP is widespread There are a lot of logiciel what are used (Skype) one network in a society

This is the end Do you have questions ?