NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL VOICE OVER INTERNET PROTOCOL UNDER THE GUIDANCE OF N. SRINIVASU SUBMITTED BY SHREETAM MOHANTY ROLL # EC200118010 SHREETAM MOHANTY [1]

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL INTRODUCTION What is VOIP ? Voice over Internet Protocol transfers voice through IP packets through the Internet. VoIP can use special hardware or a PC environment to achieve this purpose. How does VOIP works: Voice (source) - - ADC - - - - Internet - - - DAC - Voice (dest) SHREETAM MOHANTY [2]

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL PACKET FREQUENCY Packet frequency as the number of packets containing voice samples which are sent per second Components of H.323 Terminals Gateways Gatekeepers SHREETAM MOHANTY [3]

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL H.323 TERMINAL SUPPORTING OTHER PROTOCOLS H.245 : allowing the usage of the channels. Q.931: call signaling and setting up the call RTP: carries voice packets RAS: interacting with the gatekeeper SHREETAM MOHANTY [4]

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL GATEWAYS Interface between the PSTN and the Internet Translator : H.225 to H.221 or audio to video SHREETAM MOHANTY [5]

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL GATEKEEPERS Controls the end points under its zone Function Address Translation Admissions Control Call signaling Call Authorization Bandwidth Management SHREETAM MOHANTY [6]

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL H.323 PROTOCOL STACK SHREETAM MOHANTY [7]

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL DEFINITIONS Zone The collection of a gatekeeper and the endpoints registered with it is called a zone Network Address For each H.323 entity, a network address is assigned and this address uniquely identifies the H.323 entity on the network TSAP Identifier These TSAP identifiers allow multiplexing of several channels sharing the same network address SHREETAM MOHANTY [8]

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL CALL SETUP IN H.323 Endpoint enters the call setup phase Discovering a gatekeeper which would take the management of that endpoint The capability exchange takes place between the endpoint and the gatekeeper Registration of the endpoint with its gatekeeper The call is established SHREETAM MOHANTY [9]

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL MULTIPOINT CONTROL UNITS (MCU) SHREETAM MOHANTY [10]

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL SESSION INITIATION PROTOCOL (SIP) It is an application layer control protocol for creating, modifying and terminating sessions with one or more participants SHREETAM MOHANTY [11]

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL SIP MESSAGES INVITE: for inviting a user to a call BYE: for terminating a connection between the two end points ACK: invitation for reliable exchange of messages OPTIONS: for getting information about the capabilities of a call REGISTER: gives information about the location of a user to the SIP registration server. CANCEL: for terminating the search for a user SHREETAM MOHANTY [12]

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL SAMPLE SIP OPERATION SHREETAM MOHANTY [13]

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL SUPPORTING PROTOCOLS SHREETAM MOHANTY [14]

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY VOICE OVER INTERNET PROTOCOL CONCLUSION Like everything else, as the technology changes so At first, only a few companies like Cisco and Lucent offered VoIP services, but the large telecommunications carriers – such as AT&T and Sprint -- are catching on VoIP is predominately used for personal instead of enterprise-wide use, but will the people who use it. SHREETAM MOHANTY [15]