SIP.UA Configuration Parameters



String - SIP URI associated to the User Agent. This is a SIP address given to you by your provider. By default, URI is set to anonymous.X@anonymous.invalid, where X is a random token generated for each UA.


Set of WebSocket URIs to connect to. By default, the WebSocket URI is set to wss://edge.sip.onsip.com. If not specified, port 80 will be used for WS URIs and port 443 will be used for WSS URIs. This parameter can be expressed in multiple ways:

wsServers: "ws://sip-ws.example.com"
wsServers: "ws://sip-ws.example.com:8443/sip?KEY=1234"
wsServers: [
wsServers: [
  { // First connection attempt
    ws_uri: "ws://sip-ws-1.example.com",
    weight: 10
    ws_uri: "ws://sip-ws-2.example.com",
    weight: 1


If set to true, the user agent will allow NOTIFYs received without subscriptions to be emitted to a notify event listener on the UA. Default value is false.

allowLegacyNotifications: true



If enabled a malicious endpoint could take control of your client. This option should only be enabled if you have a listener on outOfDialogReferRequested event. If there is no listener, the default behavior of SIP.js is to follow the REFER. Default value is false.

allowOutOfDialogRefers: flase


Similar to sessionDescriptionHandlerFactory, this parameter allows the application to use a custom authentication model with SIP.js. The factory is passed the UA and should return credentials. Modifying this is very advanced; please refer to the source code for examples.

By default, Digest Authentication is used.


Username (String) to use when generating authentication credentials. If not defined the value in uri parameter is used.

authorizationUser: "alice123"


If set to true, the user agent calls the .start() method upon being created. Default value is true.

autostart: true


Maximum interval (Number) in seconds between WebSocket reconnection attempts. Default value is 30.

connectionRecoveryMaxInterval: 60


Minimum interval (Number) in seconds between WebSocket reconnection attempts. Default value is 2.

connectionRecoveryMinInterval: 4


Descriptive name (String) to be shown to the called party when calling or sending IM messages. It must NOT be enclosed between double quotes even if the given name contains multi-byte symbols (SIPjs will always enclose the display_name value between double quotes).

displayName: "Alice ¶€ĸøĸø"


Beta Feature

The type of DTMF that SIP.js should do, either INFO packets or in-band DTMF. In-band DTMF requires support from the Session Description Handler. Valid values are SIP.C.dtmfType.INFO and SIP.C.dtmfType.RTP. If you choose to send in-band DTMF and it fails on the Session Description Handler, then SIP.js will automatically try to send the DTMF via INFO packet. Default value is SIP.C.dtmfType.INFO. The default will change in a future release of SIP.js.

dtmfType: SIP.C.dtmfType.INFO


Set a random IP address as the host value in the Contact header field and Via sent-by parameter. Useful for SIP registrars not allowing domain names in the Contact URI. Valid values are true and false (Boolean). Default value is false.

hackIpInContact: true


Set Via transport parameter in outgoing SIP requests to “TCP”. Useful when traversing SIP nodes that are not ready to parse Via headers with “WS” or “WSS” value in a Via header. Valid values are true and false (Boolean). Default value is false.

hackViaTcp: true


Set the transport parameter to wss when used in SIP URIs. This replaces ws, which is the default and required by RFC 7118, but some SIP servers do not like that.

hackWssInTransport: true


String indicating the UUID URI to be used as instance ID to identify the UA instance when using GRUU.

instanceId: "uuid:8f1fa16a-1165-4a96-8341-785b1ef24f12"
instanceId: "8f1fa16a-1165-4a96-8341-785b1ef24f12"


Object providing the desired log behavior.

- builtinEnabled

Boolean indicating whether SIPjs should write log messages in the browser console. Default value is true.

- level

Number or String indicating the verbose level of the SIPjs log. Valid values are 3, 2, 1, 0 or "debug", "log", "warn", "error" respectively. Default value is 2 (or log).

- connector

User defined Function which will be called everytime a log is generated, according to the enabled and level options.

The function is called with the following semantics:

  level: String representing the level of the log message
('debug', 'log', 'warn', 'error')

  category: String representing the SIPjs instance class firing
the log. ie: 'sipjs.ua'

  label: String indicating the 'identifier' of the class instance
 when the log level is '3' (debug). ie: transaction.id

  content: String representing the log message
connector(level, category, label, content);


Time (in seconds) (Number) after which an incoming call is rejected if not answered. Default value is 60.

noAnswerTimeout: 120


SIP Authentication password (String). Default value is null.

password: "1234"


Indicate if a SIP User Agent should register automatically when starting. Valid values are true and false (Boolean). Default value is true.

register: false


Registration expiry time (in seconds) (Number). Default value is 600.

registerExpires: 300


Set the SIP registrar URI. Valid value is a SIP URI without username. Default value is null which means that the registrar URI is taken from the uri parameter (by removing the username).

registrarServer: 'sip:registrar.mydomain.com'


Constant representing whether the UA should do 100rel. Accepts SIP.C.supported.REQUIRED, SIP.C.supported.SUPPORTED, and SIP.C.supported.UNSUPPORTED. Default value is SIP.C.supported.UNSUPPORTED.

rel100: SIP.C.supported.REQUIRED


Constant representing whether the UA should support the SIP Replaces header. If you enable support for Replaces, please be sure to listen for the replaced event event on each Session. Accepts SIP.C.supported.SUPPORTED, and SIP.C.supported.UNSUPPORTED. Default value is SIP.C.supported.UNSUPPORTED.

replaces: SIP.C.supported.SUPPORTED


function that is a factory for generating sessionDescriptionHandlers. The factory will be passed a session object for the current session and the sessionDescriptionHandlerFactoryOptions object defined on the UA.

See the WebRTC SessionDescriptionHandler documentation for more information on how to create this factory.

sessionDescriptionHandlerFactory: function(session, options) {
  return new SessionDescriptionHandler(session, options);


Options that will be passed to the SessionDescriptionHandlerFactory.


Indicate whether incoming and outgoing SIP request/responses must be logged in the browser console (Boolean). Default value is false.

traceSip: true


If set to true every SIP initial request sent by SIP.js includes a Route header with the SIP URI associated to the WebSocket server as value. Some SIP Outbound Proxies require such a header. Valid values are true and false (Boolean). Default value is false.

wsServers: "ws://example.org/sip-ws"
usePreloadedRoute: true

The Route header will look like Route: <sip:example.org;lr;transport=ws>

wsServers: "wss://example.org:8443"
usePreloadedRoute: true

The Route header will look like Route: <sip:example.org:8443;lr;transport=ws>


If this is set then the User-Agent header will have this string appended after name and version.

userAgentString: "myAwesomeApp"

The User-Agent header will look like User-Agent: myAwesomeApp


The number of times to attempt to reconnect to a WebSocket when the connection drops. The default value is 3.


The time (in seconds) to wait between WebSocket reconnection attempts. The default timeout is 4 seconds.