Axis I8016-LVE - Page 13

AXISI8016-LVENetworkVideoIntercom
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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
SIP
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UseragentA-intercom.SIPaddress:sip:192.168.1.101
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UseragentB-SIP-enabledphone.SIPaddress:sip:192.168.1.100
YoucansetuptheAxisintercomtocallforexampleaSIP-enabledphoneonthesamenetworkusingapeer-to-peerSIPsetup.
PrivateBranchExchange(PBX)
WhenyoumakeSIPcallsoutsideyourlocalIPnetwork,aPrivateBranchExchange(PBX)canactasacentralhub.Themain
componentofaPBXisaSIPserver,whichisalsoreferredtoasaSIPproxyoraregistrar.APBXworkslikeatraditionalswitchboard,
showingtheclient'scurrentstatusandallowingforexamplecalltransfers,voicemail,andredirections.
ThePBXSIPservercanbesetupasalocalentityoroffsite.Itcanbehostedonanintranetorbyathirdpartyprovider.Whenyou
makeSIPcallsbetweennetworks,callsareroutedthroughasetofPBXs,thatquerythelocationoftheSIPaddresstobereached.
EachSIPuseragentregisterswiththePBX,andcanthenreachtheothersbydialingthecorrectextension.AtypicalSIPaddressin
thiscasewouldbesip:<user>@<domain>orsip:<user>@<registrar-ip>.TheSIPaddressisindependentofitsIP
addressandthePBXmakesthedeviceaccessibleaslongasitisregisteredtothePBX.
Example
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