Axis I8116-E - Learn More; Voice over IP (VoIP) Explained; Session Initiation Protocol (SIP)

AXISI8116-ENetworkVideoIntercom
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VoiceoverIP(VoIP)
VoiceoverIP(VoIP)isagroupoftechnologiesthatenablesvoicecommunicationandmultimediasessionsoverIPnetworks,suchas
theinternet.Intraditionalphonecalls,analogsignalsaresentthroughcircuittransmissionsoverthePublicSwitchedTelephone
Network(PSTN).InaVoIPcall,analogsignalsareturnedintodigitalsignalstomakeitpossibletosendthemindatapackets
acrosslocalIPnetworksortheinternet.
IntheAxisproduct,VoIPisenabledthroughtheSessionInitiationProtocol(SIP)andDual-ToneMulti-Frequency(DTMF)signaling.
Example
WhenyoupressthecallbuttononanAxisintercom,acallisinitiatedtooneormorepredenedrecipients.Whenarecipientreplies,
acallisestablished.ThevoiceandvideoistransferredthroughVoIPtechnologies.
SessionInitiationProtocol(SIP)
TheSessionInitiationProtocol(SIP)isusedtosetup,maintainandterminateVoIPcalls.Youcanmakecallsbetweentwoormore
parties,calledSIPuseragents.TomakeaSIPcallyoucanuse,forexample,SIPphones,softphonesorSIP-enabledAxisdevices.
TheactualaudioorvideoisexchangedbetweentheSIPuseragentswithatransportprotocol,forexampleRTP(Real-Time
TransportProtocol).
Youcanmakecallsonlocalnetworksusingapeer-to-peersetup,oracrossnetworksusingaPBX.
Peer-to-peerSIP(P2PSIP)
ThemostbasictypeofSIPcommunicationtakesplacedirectlybetweentwoormoreSIPuseragents.Thisiscalledpeer-to-peerSIP
(P2PSIP).Ifittakesplaceonalocalnetwork,allthat’sneededaretheSIPaddressesoftheuseragents.AtypicalSIPaddressinthis
casewouldbesip:<local-ip>.
Example
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