The verb's noun lets you set up VoIP sessions by using SIP -- Session Initiation Protocol. With this feature, you can send a call to any SIP ...
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Theverb'snounletsyousetupVoIPsessionsbyusingSIP--SessionInitiationProtocol.Withthisfeature,youcansendacalltoanySIPendpoint.SetupyourTwiMLtousethenounwithintheverbwheneveranyofyourTwiliophonenumbersarecalled.IfyouareunfamiliarwithSIP,orwantmoreinformationonhowTwilioworkswithyourSIPendpoint,pleaseseetheSIPoverview.
TheSIPsession
TheSIPINVITEmessageincludestheAPIversion,theAccountSid,andCallSidforthecall.Optionally,youcanalsoprovideasetofparameterstomanagesignalingtransportandauthentication,orconfigureTwiliotopasscustomSIPheadersintheINVITEmessage:thismethodincludesheaderssuchasUUI(User-to-userInformation).
OncetheSIPsessioncompletes,TwiliorequeststheactionURL,passingalongtheSIPCallIDheader,theresponsecodeoftheinviteattempt,anyX-headerspassedbackonthefinalSIPresponse,aswellasthestandardTwilioparameters.
IfEnhancedProgrammableSIPFeaturesisnotenabledonyouraccount,onlyonenounmaybespecifiedper,andtheINVITEmessagemaybesenttoonlyoneSIPendpoint.Also,youcannotaddanyothernouns(eg,)inthesameastheSIP.Ifyouwanttouseanothernoun,setupacallbackonthetousealternatemethods.
Theregionparameter
TospecifythegeographicregionfromwhichTwiliowillsendSIP-outtraffictowardsyourcommunicationinfrastructure,youmustincludetheregionparameterinyourSIPURI.Forexample,iftheregion=ie1parameterisincludedinyourSIPURI,TwiliowillsendtheSIPtrafficfromtheEuropeIrelandregion:
sip:[email protected];region=ie1
Region
Location
us1
NorthAmericaVirginia
us2
NorthAmericaOregon
ie1
EuropeIreland
de1
EuropeFrankfurt
sg1
AsiaPacificSingapore
jp1
AsiaPacificTokyo
br1
SouthAmericaSãoPaulo
au1
AsiaPacificSydney
Iftheregionparameterisnotspecified,TwiliowillsendSIP-outtrafficfromtheNorthAmericaVirginiaregion.
UsetheSipnoun
Alloftheexistingparametersworkwiththenoun(record,timeout,hangupOnStar,etc).ForSIPcalls,thecallerIdattributedoesnotneedtobeavalidatedphonenumber.Enteranyalphanumericstring.Optionallyincludethefollowingchars:+-_.,butnowhitespace.
Withinthenoun,youmustspecifyaURIforTwiliotoconnectto.TheURIshouldbeavalidSIPURIunder255characters.Forexample:
YouareviewinganoutdatedversionofthisSDK.
Showsampleresponse
ExampleJSONresponse
Showcode
Usethenoun
Authentication
SendusernameandpasswordattributesforauthenticationtoyourSIPinfrastructureasattributesonthenoun.
AttributeName
Values
username
UsernameforSIPauthentication
password
PasswordforSIPauthentication
Forexample:
YouareviewinganoutdatedversionofthisSDK.
Showsampleresponse
ExampleJSONresponse
Showcode
Authenticationwithyour
Customheaders
SendcustomheadersbyappendingthemtotheSIPURI--justasyou'dpassheadersinaURIoverHTTP.Forexample:
YouareviewinganoutdatedversionofthisSDK.
Showsampleresponse
ExampleJSONresponse
Showcode
Customheaderswith
WhiletheSIPURIitselfmustbeunder255chars,theheadersmustbeunder1024characters.Anyheadersstartingwiththex-prefixcanbesentthisway.
Youcanalsosendmultipleparametersandvaluesaspartofthex-header
sip:[email protected]?x-customname=Madhu%2CMathiyalagan%3BTitle%3DManager&x-myotherheader=bar
UUI(User-to-UserInformation)headercanbesentwithoutprependingx-
sip:[email protected]?User-to-User=123456789%3Bencoding%3Dhex&x-myotherheader=bar
Transport
SetaparameteronyourSIPURItospecifywhattransportprotocolyouwanttouse.Currently,thisislimitedtoUDP,TCPandTLS.Bydefault,TwiliosendsyourSIPINVITEoverUDP.Changethisbyusingthetransportparameter:
YouareviewinganoutdatedversionofthisSDK.
Showsampleresponse
ExampleJSONresponse
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Transportwith
Alternatively,youmaycustomizeittouseTLSforSIPsignaling.WhenusingTLS,thedefaultportwillbe5061however,adifferentonemaybespecified.
YouareviewinganoutdatedversionofthisSDK.
Showsampleresponse
ExampleJSONresponse
Showcode
TLSTransportwith
Callparameters
WhenaSIPcallisanswered,TwiliopassesthefollowingparameterswithitsrequestinadditiontothestandardTwiMLVoicerequestparameters:
Parameter
Values
Called
ToheaderoftheSIPInvitemessage.TheSIPidentifierofthecalledparty.
Caller
FromheaderoftheSIPInvitemessage.TheSIPidentifierofthepartythatinitiatedthecall.
SipCallId
TheSIPcallIDheaderoftherequestmadetotheremoteSIPinfrastructure.
SipDomain
ThehostpartoftheSIPrequest.
SipDomainSid
YourSIPDomainID.Itis34characterslong,andalwaysstartswiththelettersSD.
SipHeader_
Thename/valueofanyX-headersreturnedinthe200responsetotheSIPINVITErequest.ThisisapplicableonlyifyouareusingSIPcustomheaders.
SipSourceIp
SourceIPaddressforSIPsignaling.
Additionalparameters
Whenyouinvokedialactionattributeand,Twiliopassesthefollowingparameterswithitsrequestinadditiontothestandarddialactionparameters.UsetheactioncallbackparameterstomodifyyourapplicationbasedontheresultsoftheSIPdialattempt:
Parameter
Values
DialSipCallId
TheSIPcallIDheaderoftherequestmadetotheremoteSIPinfrastructure.
DialSipResponseCode
TheSIPresponsecodeasaresultoftheINVITEattempt.
DialSipHeader_
Thename/valueofanyX-headersreturnedinthefinalresponsetotheSIPINVITErequest.
Attributes
Thenounsupportsthefollowingattributesthatmodifyitsbehavior:
AttributeName
AllowedValues
DefaultValue
method
GET,POST
POST
password
PasswordforSIPauthentication
statusCallbackEvent
initiated,ringing,answered,completed
none
statusCallback
anyurl
none
statusCallbackMethod
GET,POST
POST
url
callscreeningurl
none
username
UsernameforSIPauthentication
url
TheurlattributeallowsyoutospecifyaurlforaTwiMLdocumentthat
runsonthecalledparty'send,aftertheyanswer,butbeforethetwopartiesare
connected.YoucanusethisTwiMLtoprivatelyorinformationtothe
calledparty,orprovideachancetodeclinethephonecallusing
and.IfanswerOnBridgeattributeisusedon,
thecurrentcallerwillcontinuetohearringingwhiletheTwiMLdocumentexecutesontheotherend.
TwiMLdocumentsexecutedinthismannerarenotallowedtocontaintheverb.
method
ThemethodattributeallowsyoutospecifywhichHTTPmethodTwilioshould
usewhenrequestingtheURLspecifiedintheurlattribute.ThedefaultisPOST.
statusCallbackEvent
Whendialingouttoanumberusing,anoutboundcallisinitiated.The
calltransitionsfromtheinitiatedstatetotheringingstatewhenthe
phonestartsringing.Ittransitionstotheansweredstatewhenthecallis
pickedup,andfinallytothecompletedstatewhenthecallisover.With
statusCallbackEvent,youcansubscribetoreceivewebhooksforthedifferent
callprogressevents:initiated,ringing,answered,orcompletedfora
givencall.
ThestatusCallbackEventattributeallowsyoutospecifywhicheventsTwilio
shouldwebhookon.Tospecifymultipleeventsseparatethemwithaspace:
initiatedringingansweredcompleted.IfastatusCallbackisprovidedandno
statuscallbackeventsarespecifiedthecompletedeventwillbesentbydefault.
AsopposedtocreatinganoutboundcallviatheAPI,outboundcallscreated
usingareinitiatedrightawayandneverqueued.Thefollowingshowsa
timelineofpossiblecalleventsthatcanbereturnedandthedifferentcall
statusesthatalegmayexperience:
Event
Description
initiated
TheinitiatedeventisfiredwhenTwiliostartsdialingthecall.
ringing
Theringingeventisfiredwhenthecallstartsringing.
answered
Theansweredeventisfiredwhenthecallisanswered.
completed
Thecompletedeventisfiredwhenthecalliscompleted,regardlessoftheterminationstatus:busy,canceled,completed,failed,orno-answer.IfnoStatusCallbackEventisspecified,completedwillbefiredbydefault.
statusCallback
ThestatusCallbackattributeallowsyoutospecifyaURLforTwiliotosend
webhookrequeststooneacheventspecifiedinthestatusCallbackEvent
attribute.Non-relativeURLsmustcontainavalidhostname(underscoresarenotpermitted).
TheparametersTwiliopassestoyourapplicationinitsasynchronousrequestto
theStatusCallbackURLincludeallparameterspassedinasynchronousrequest
toretrieveTwiMLwhenTwilioreceivesacalltooneofyourTwilionumbers.
ThefulllistofparametersanddescriptionsofeachareintheTwiMLVoice
Requestdocumentation.
Whenthecallprogresseventsarefired,theStatusCallbackrequestalsopassestheseadditionalparameters:
Parameter
Description
CallSid
Auniqueidentifierforthiscall,generatedbyTwilio.YoucanusetheCallSidtomodifythechildcallbyPOSTingtoCalls/{CallSid}withanewTwiMLURL.
ParentCallSid
Auniqueidentifierfortheparentcall.
CallStatus
Adescriptivestatusforthecall.Thevalueisoneofqueued,initiated,ringing,in-progress,busy,failed,orno-answer.SeetheCallStatussectionformoredetails.
CallDuration
Thedurationinsecondsofthejust-completedcall.Onlypresentinthecompletedevent.
RecordingUrl
TheURLofthephonecall'srecordedaudio.Thisparameterisincludedonlyifrecordissetontheanddoesnotincluderecordingsinitiatedinotherways.RecordingUrlisonlypresentinthecompletedevent.
RecordingSid
TheuniqueIDoftheRecordingfromthiscall.RecordingSidisonlypresentinthecompletedevent.
RecordingDuration
Thedurationoftherecordedaudio(inseconds).RecordingDurationisonlypresentinthecompletedevent.Togetafinalaccuraterecordingdurationafteranytrimmingofsilence,userecordingStatusCallback.
Timestamp
Thetimestampwhentheeventwasfired,givenasUTCinRFC2822format.
CallbackSource
Astringthatdescribesthesourceofthewebhook.Thisisprovidedtohelpdisambiguatewhythewebhookwasmade.OnStatusCallbacks,thisvalueisalwayscall-progress-events.
SequenceNumber
Theorderinwhichtheeventswerefired,startingfrom0.Althougheventsarefiredinorder,theyaremadeasseparateHTTPrequestsandthereisnoguaranteetheywillarriveinthesameorder.
statusCallbackMethod
ThestatusCallbackMethodattributeallowsyoutospecifywhichHTTPmethod
TwilioshouldusewhenrequestingtheURLinthestatusCallbackattribute.
ThedefaultisPOST.
Examples
Example1:DialingtoaSIPendpoint
Inthisexample,[email protected],useaverbwithanounnestedinside.
YouareviewinganoutdatedversionofthisSDK.
Showsampleresponse
ExampleJSONresponse
Showcode
DialingtoaSIPendpoint
Example2:DialaSIPendpoint,protectedbyauthentication
Inthisexample,youarestilldialingKate,butyouneedtopassauthenticationcredentialstoreachher.
YouareviewinganoutdatedversionofthisSDK.
Showsampleresponse
ExampleJSONresponse
Showcode
DialaSIPendpoint,protectedbyauthentication
Example3:Passingheaders
Inthisexample,passcustomheadersalongwiththeSIPaddress.
YouareviewinganoutdatedversionofthisSDK.
Showsampleresponse
ExampleJSONresponse
Showcode
Passingheaders
Example4:Dialwithseveralattributes
AmorecomplexDial,specifyingcustomsettingsasattributeson,includingcallscreening.
YouareviewinganoutdatedversionofthisSDK.
Showsampleresponse
ExampleJSONresponse
Showcode
Dialwithseveralattributes
Example5:CallProgressEvents
Inthisexample,wewanttoreceiveawebhookforeachcallprogresseventwhen
dialingaSIPendpointusing.
YouareviewinganoutdatedversionofthisSDK.
Showsampleresponse
ExampleJSONresponse
Showcode
CallProgressEvents
Example6:ParallelCallingorSimultaneousDialing
InordertousetheSIPParallelCallingTwiliofeature,youmustenablethe"EnhancedProgrammableSIPFeatures"inyourVoicesettingsintheConsole.
Parallelcalling,alsoknownassimultaneousdialing,isusefulwhenyouhaveseveralphones(orseveralpeople)thatyouwanttoringwhenyoureceiveanincomingcall.Sayyouhavemultipledifferentendpointswhereyoucantakeacall,suchasamobilephone,homephone,officephone,and/orPCsoftphone.Thisfeatureallowsyoutocalluptotenendpointsatthesametimebyspecifyingaverbwithmultipledestinations.Additionally,foreachendpoint,youcanspecifywhichStatusCallbackeventsforwhichyouwanttoreceiveWebhookrequests.
Inadditiontophonenumbersand/orTwilioClientidentifiers,youcannowspecifySIPURIsforparallelcallingusingtheverb’snoun.
Youcanmixuptotendifferent,,ornounswithinaDialverbtocallsimultaneously.
Keepinmindthatthefirstcallthatconnectswillcancelalltheotherattempts.Ifyoudialanofficephonesystemoramobilephoneinairplanemode,etc.,thatendpointmaypickupafterasinglering,preventingtheotherendpointsfromringinglongenoughforahumantoeveranswer.Henceyoushouldtakecaretousesimultaneousdialinginsituationswhereyouknowthebehaviorofthecalledparties.
Fortheexample,AlicehasthreedifferentwaystocontactherusingSIP.ShewantsyoutoringheronherSIPsoftphone,SIPdeskphoneandSIPmobileclientatthesametime,andshewillpickuponedependingonwheresheisatthetimeofthecall.
YouareviewinganoutdatedversionofthisSDK.
Showsampleresponse
ExampleJSONresponse
Showcode
Parallelcalling
Example7:SerialCallingorSequentialDialing
InordertousetheSIPSerialCallingTwiliofeature,youmustenablethe"EnhancedProgrammableSIPFeatures"inyourVoicesettingsintheConsole.
Serialcalling,alsoknownassequentialdialing,isusefulwhenyouhaveseveralphones(orseveralpeople)thatyouwanttoringinaspecificorderwhenyoureceiveanincomingcall.Sayyouhaveagroupofagentsinacallcenter,andyouwanttotryeachoftheminorderuntiloneofthempicksup.Thisfeatureallowsyoutocalluptotenagentssequentiallybyspecifyingaverbwithmultipledestinations,andsettingthesequentialattributetotrue.Thepriorityofthecallsisbasedontheorderwithintheverb.Additionally,foreachendpoint,youcanspecifywhichStatusCallbackeventsyouwanttoreceiveviaWebhooks.
Youcanmixuptotendifferent,,ornounswithinaverbtocallsequentially.
Keepinmindthatthefirstcallthatconnectswillcancelalltheremainingattemptsinthesequence.Ifyoudialanofficephonesystemoramobilephoneinairplanemode,etc.,thatendpointmaypickupafterasinglering,preventingtheremainingendpointsfrombeingcalled.Henceyoushouldtakecaretousesequentialdialinginsituationswhereyouknowthebehaviorofthecalledparties.
Fortheexamplebelow,ifAlicerejectsordoesnotanswerthenthecallwillgotoBob.SimilarlyifBobrejectsordoesnotanswerthenthecallwillgotoCharlie.IfCharliedoesnotanswer,thecallwillfail.
YouareviewinganoutdatedversionofthisSDK.
Showsampleresponse
ExampleJSONresponse
Showcode
Serialcalling
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