Srf

Applications create an instance of Srf in order to create and manage SIP Dialogs and SIP transactions. An application may have one or more Srf instances, although for most cases a single instance is sufficient.

• Srf

  • new Srf(tag)

  • instance

    • .createUAS(req, res, opts, [callback])

    • .createUAC(uri, opts, [progressCallbacks], [callback])

    • .createB2BUA(req, res, uri, opts, [progressCallbacks], [callback])

    • .proxyRequest(req, [destination], [opts], [callback])

    • .request(uri, opts, method, [body], [callback])

    • .findDialogById(stackDialogId)

    • .findDialogByCallIDAndFromTag(callId, tag)

    • .request(uri, opts, [headers], [body], [callback])

    • .connect(opts)

    • .listen(opts)

    • .endSession(msg)

    • "connect" (err, hostport)

    • "error" (err)

    • "cdr:attempt" (source, time, msg)

    • "cdr:start" (source, time, role, msg)

    • "cdr:stop" (source, time, reason, msg)

  • static

    • .Dialog

    • .SipError

    • .parseUri

new Srf(tag)

Param	Type	Description
tag	string | Array	a string or array of strings, representing tag values for this application. Tags can be used in conjunction with a call routing web callback to direct requests to particular applications.

Creates an instance of an signaling resource framework.

srf.createUAS(req, res, opts, [callback])

Param	Type	Description
req	Object	the incoming sip request object
res	Object	the sip response object
opts	Object	configuration options
opts.localSdp	string	the local session description protocol to include in the SIP response
[opts.headers]	Object	SIP headers to include on the SIP response to the INVITE
[callback]	function	if provided, callback with signature (err, dialog)

create a SIP dialog, acting as a UAS (user agent server); i.e. respond to an incoming SIP INVITE with a 200 OK (or to a SUBSCRIBE request with a 202 Accepted).

Note that the Dialog is generated (i.e. the callback invoked / the Promise resolved) at the moment that the 200 OK is sent back towards the requestor, not when the ACK is subsequently received.

Returns: Srf | Promise - if a callback is supplied, a reference to the Srf instance.
If no callback is supplied, then a Promise that is resolved with the sip dialog that is created.
Example (returning a Promise)

const Srf = require('drachtio-srf');
const srf = new Srf();

srf.invite((req, res) => {
  const mySdp; // populated somehow with SDP we want to answer in 200 OK
  srf.createUas(req, res, {localSdp: mySdp})
    .then((uas) => {
      console.log(`dialog established, remote uri is ${uas.remote.uri}`);
      uas.on('destroy', () => {
        console.log('caller hung up');
      });
    })
    .catch((err) => {
      console.log(`Error establishing dialog: ${err}`);
    });
});

Example (using callback)

const Srf = require('drachtio-srf');
const srf = new Srf();

srf.invite((req, res) => {
  const mySdp; // populated somehow with SDP we want to offer in 200 OK
  srf.createUas(req, res, {localSdp: mySdp},
    (err, uas) => {
      if (err) {
        return console.log(`Error establishing dialog: ${err}`);
      }
      console.log(`dialog established, local tag is ${uas.sip.localTag}`);
      uas.on('destroy', () => {
        console.log('caller hung up');
      });
    });
});

Example (specifying standard or custom headers)

srf.createUas(req, res, {
    localSdp: mySdp,
    headers: {
      'User-Agent': 'drachtio/iechyd-da',
      'X-Linked-UUID': '1e2587c'
    }
  }).then((uas) => { ..});

srf.createUAC(uri, opts, [progressCallbacks], [callback])

Param	Type	Description
uri	string	request uri to send to
opts	Object	configuration options
[opts.headers]	Object	SIP headers to include on the SIP INVITE request
opts.localSdp	string	the local session description protocol to include in the SIP INVITE request
[opts.proxy]	string	send the request through an outbound proxy, specified as full sip uri or address[:port]
opts.auth	Object | function	sip credentials to use if challenged, or a function invoked with (req, res) and returning (err, username, password) where req is the request that was sent and res is the response that included the digest challenge
opts.auth.username	string	sip username
opts.auth.password	string	sip password
[progressCallbacks]	Object	callbacks providing call progress notification
[progressCallbacks.cbRequest]	function	callback that provides request sent over the wire, with signature (req)
[progressCallbacks.cbProvisional]	function	callback that provides a provisional response with signature (provisionalRes)
[callback]	function	if provided, callback with signature (err, dialog)

create a SIP dialog, acting as a UAC (user agent client)

Returns: Srf | Promise - if a callback is supplied, a reference to the Srf instance.
If no callback is supplied, then a Promise that is resolved with the sip dialog that is created.
Example (returning a Promise)

const Srf = require('drachtio-srf');
const srf = new Srf();

const mySdp; // populated somehow with SDP we want to offer
srf.createUac('sip:1234@10.10.100.1', {localSdp: mySdp})
  .then((uac) => {
    console.log(`dialog established, call-id is ${uac.sip.callId}`);
    uac.on('destroy', () => {
      console.log('called party hung up');
    });
  })
  .catch((err) => {
    console.log(`INVITE rejected with status: ${err.status}`);
  });
});

Example (Using a callback)

const Srf = require('drachtio-srf');
const srf = new Srf();

const mySdp; // populated somehow with SDP we want to offer
srf.createUac('sip:1234@10.10.100.1', {localSdp: mySdp},
   (err, uac) => {
     if (err) {
       return console.log(`INVITE rejected with status: ${err.status}`);
     }
    uac.on('destroy', () => {
      console.log('called party hung up');
    });
  });

Example (Canceling a request by using a progress callback)

const Srf = require('drachtio-srf');
const srf = new Srf();

const mySdp; // populated somehow with SDP we want to offer
let inviteSent;
srf.createUAC('sip:1234@10.10.100.1', {localSdp: mySdp},
  {
    cbRequest: (reqSent) => { inviteSent = req; }
  })
  .then((uac) => {
    // unexpected, in this case
    console.log('dialog established before we could cancel');
  })
  .catch((err) => {
    assert(err.status === 487); // expected sip response to a CANCEL
  });
});

// cancel the request after 0.5s
setTimeout(() => {
  inviteSent.cancel();
}, 500);

srf.createB2BUA(req, res, uri, opts, [progressCallbacks], [callback])

Param	Type	Default	Description
req	Object		incoming sip request object
res	Object		incoming sip response object
uri	string		sip uri or IP address[:port] to send the UAC INVITE to
opts	Object		configuration options
[opts.headers]	Object		SIP headers to include on the SIP INVITE request to the B party
[opts.responseHeaders]	Object		SIP headers to include on responses to the A party. Either an object containing SIP headers, or a function returning an object may be provided. If a function is provided, it will be called with the signature (uacRes, headers), where 'uacRes' is the response received from the B party, and 'headers' are the SIP headers that have currently been set for the response.
[opts.localSdpA]	string | function		the local session description protocol to offer in the response to the SIP INVITE request on the A leg; either a string or a function may be provided. If a function is provided, it will be invoked with two parameters (sdp, res) correspnding to the SDP received from the B party, and the sip response object received on the response from B. The function must return either the SDP (as a string) or a Promise that resolves to the SDP. If no value is provided (neither string nor function), then the SDP returned by the B party in the provisional/final response on the UAC leg will be sent back to the A party in the answer.
[opts.localSdpB]	string		the local session description protocol to offer in the SIP INVITE request on the B leg
[opts.proxyRequestHeaders]	Array		an array of header names which, if they appear in the INVITE request on the A leg, should be included unchanged on the generated B leg INVITE
[opts.proxyResponseHeaders]	Array		an array of header names which, if they appear in the response to the outgoing INVITE, should be included unchanged on the generated response to the A leg
[opts.passFailure]	Boolean	true	specifies whether to pass a failure returned from B leg back to the A leg
[opts.passProvisionalResponses]	Boolean	true	specifies whether to pass provisional responses from B leg back to the A leg
[opts.proxy]	string		send the request through an outbound proxy, specified as full sip uri or address[:port]
opts.auth	Object | function		sip credentials to use if challenged, or a function invoked with (req, res) and returning (err, username, password) where req is the request that was sent and res is the response that included the digest challenge
opts.auth.username	string		sip username
opts.auth.password	string		sip password
[progressCallbacks]	Object		callbacks providing call progress notification
[progressCallbacks.cbRequest]	function		callback that provides request sent over the wire, with signature (req)
[progressCallbacks.cbProvisional]	function		callback that provides a provisional response with signature (provisionalRes)
[progressCallbacks.cbFinalizedUac]	function		callback that provides the UAC dialog as soon as the 200 OK is received from the B party. Since the UAC dialog is also returned when the B2B has been completely constructed, this is mainly useful if there is some need to be notified as soon as the B party answers. The callback signature is (uac).
[callback]	function		if provided, callback with signature (err, {uas, uac})

create back-to-back dialogs; i.e. act as a back-to-back user agent (B2BUA), creating a pair of dialogs {uas, uac} -- a UAS dialog facing the caller or A party, and a UAC dialog facing the callee or B party such that media flows between them

Returns: Srf | Promise - if a callback is supplied, a reference to the Srf instance.
If no callback is supplied, then a Promise that is resolved with the sip dialog that is created.
Example (simple B2BUA)

const Srf = require('drachtio-srf');
const srf = new Srf();

srf.invite((req, res) => {
  srf.createB2BUA('sip:1234@10.10.100.1', req, res, {localSdpB: req.body})
    .then(({uas, uac}) => {
      console.log('call connected');

      // when one side terminates, hang up the other
      uas.on('destroy', () => { uac.destroy(); });
      uac.on('destroy', () => { uas.destroy(); });
    })
    .catch((err) => {
      console.log(`call failed to connect: ${err}`);
    });
});

Example (use opts.passFailure to attempt a fallback URI on failure)

const Srf = require('drachtio-srf');
const srf = new Srf();

function endCall(dlg1, dlg2) {
  dlg1.on('destroy', () => {dlg2.destroy();})
  dlg2.on('destroy', () => {dlg1.destroy();})
}
srf.invite((req, res) => {
  srf.createB2BUA('sip:1234@10.10.100.1', req, res, {localSdpB: req.body, passFailure: false})
    .then({uas, uac} => {
      console.log('call connected to primary destination');
      endcall(uas, uac);
    })
    .catch((err) => {
      // try backup if we got a sip non-success response and the caller did not hang up
      if (err instanceof Srf.SipError && err.status !== 487) {
          console.log(`failed connecting to primary, will try backup: ${err}`);
          srf.createB2BUA('sip:1234@10.10.100.2', req, res, {
            localSdpB: req.body}
          })
            .then({uas, uac} => {
              console.log('call connected to backup destination');
              endcall(uas.uac);
            })
            catch((err) => {
              console.log(`failed connecting to backup uri: ${err}`);
            });
      }
    });
});

Example (B2BUA with media proxy using rtpengine)

const Srf = require('drachtio-srf');
const srf = new Srf();
const rtpengine = require('rtpengine-client').Client

// helper functions

// clean up and free rtpengine resources when either side hangs up
function endCall(dlg1, dlg2, details) {
  [dlg1, dlg2].each((dlg) => {
    dlg.on('destroy', () => {(dlg === dlg1 ? dlg2 : dlg1).destroy();});
    rtpengine.delete(details);
  });
}

// function returning a Promise that resolves with the SDP to offer A leg in 18x/200 answer
function getSdpA(details, remoteSdp, res) {
  return rtpengine.answer(Object.assign(details, {
    'sdp': remoteSdp,
    'to-tag': res.getParsedHeader('To').params.tag
   }))
    .then((response) => {
      if (response.result !== 'ok') throw new Error(`Error calling answer: ${response['error-reason']}`);
      return response.sdp;
   })
}

// handle incoming invite
srf.invite((req, res) => {
  const from = req.getParsedHeader('From');
  const details = {'call-id': req.get('Call-Id'), 'from-tag': from.params.tag};

  rtpengine.offer(Object.assign(details, {'sdp': req.body})
    .then((rtpResponse) => {
      if (rtpResponse && rtpResponse.result === 'ok') return rtpResponse.sdp;
      throw new Error('rtpengine failure');
    })
    .then((sdpB) => {
      return srf.createB2BUA('sip:1234@10.10.100.1', req, res, {
        localSdpB: sdpB,
        localSdpA: getSdpA.bind(null, details)
      });
    })
    .then({uas, uac} => {
      console.log('call connected with media proxy');
      endcall(uas, uac, details);
    })
    .catch((err) => {
      console.log(`Error proxying call with media: ${err}`);
    });
});

srf.proxyRequest(req, [destination], [opts], [callback])

Param	Type	Default	Description
req	Request		drachtio request object representing an incoming SIP request
[destination]	String | Array		an IP address[:port], or list of same, to proxy the request to
[opts]	Object		configuration options for the proxy operation
[opts.forking]	String	sequential	when multiple destinations are provided, this option governs whether they are attempted sequentially or in parallel. Valid values are 'sequential' or 'parallel'
[opts.remainInDialog]	Boolean	false	if true, add Record-Route header and remain in the SIP dialog (i.e. receiving futher SIP messaging for the dialog, including the terminating BYE request). Alias: recordRoute.
[opts.provisionalTimeout]	String		timeout after which to attempt the next destination if no 100 Trying response has been received. Examples of valid syntax for this property is '1500ms', or '2s'
[opts.finalTimeout]	String		timeout, in milliseconds, after which to cancel the current request and attempt the next destination if no final response has been received. Syntax is the same as for the provisionalTimeout property.
[opts.followRedirects]	Boolean	false	if true, handle 3XX redirect responses by generating a new request as per the Contact header; otherwise, proxy the 3XX response back upstream without generating a new response
[callback]	function		callback invoked when proxy operation completes, signature (err, results) where results is a JSON object describing the individual sip call attempts and results

proxy an incoming request

Returns: Srf | Promise - returns a Promise if no callback is supplied, otherwise the Srf object
Example (simple proxy)

const Srf = require('drachtio-srf');
const srf = new Srf();

srf.invite((req, res) => {
  srf.proxyRequest(req, 'sip.example.com');
});

Example (proxy with options)

const Srf = require('drachtio-srf');
const srf = new Srf();

srf.invite((req, res) => {
  srf.proxyRequest(req, ['sip.example1.com', 'sip.example2.com'], {
    recordRoute: true,
    followRedirects: true,
    provisionalTimeout: '2s'
  }).then((results) => {
    console.log(JSON.stringify(result)); // {finalStatus: 200, finalResponse:{..}, responses: [..]}
  });
});

srf.request(uri, opts, method, [body], [callback])

Param	Type	Description
uri	String	request-uri
opts	Object	options
method	String	SIP method for the request
[opts.headers]	Object	SIP headers to include on the request
[body]	String	body to include with the request
[opts.auth]	Object	authentication to use if challenged
[opts.auth.username]	String	sip username
[opts.auth.password]	String	sip password
[callback]	function	callback invoked when request is sent, signature (err, requestSent) where requestSent is a SipRequest sent out over the wire

Send an outbound request outside of a Dialog.

Returns: Srf | Promise - returns a Promise if no callback is supplied, otherwise the Srf object

srf.findDialogById(stackDialogId)

Param	Type	Description
stackDialogId	String	dialog id

Returns an existing dialog for a given dialog id, if it exists

srf.findDialogByCallIDAndFromTag(callId, tag)

Param	Type	Description
callId	String	SIP Call-ID
tag	String	SIP From tag

Returns an existing dialog for a given sip call-id and from tag, if it exists

srf.request(uri, opts, [headers], [body], [callback])

Param	Type	Description
uri	string	sip request-uri to send request to
opts	Object	configuration options
opts.method	String	SIP method to send (lower-case)
[headers]	Object	SIP headers to apply to the outbound request
[body]	String	body to send with the SIP request
[opts.proxy]	string	send the request through an outbound proxy, specified as full sip uri or address[:port]
[callback]	function	callback invoked when sip request has been sent, invoked with signature (err, request) where request is a sip request object representing the sip message that was sent.

send a SIP request outside of a dialog

Example (sending OPTIONS request)

srf.request('sip.example.com', {
  method: 'OPTIONS',
  headers: {
    'User-Agent': 'drachtio'
  }
 }, (err, req) => {
  req.on('response', (res) => {
    console.log(`received ${res.statusCode} response`);
  });
});

srf.connect(opts)

Param	Type	Default	Description
opts	Object		connection options
[opts.host]	string	"127.0.0.1"	address drachtio server is listening on for client connections
[opts.port]	Number	9022	address drachtio server is listening on for client connections
opts.secret	String		shared secret used to authenticate connections

make an inbound connection to a drachtio server

Example

const Srf = require('drachtio-srf');
const srf = new Srf();

srf.connect({host: '127.0.0.1', port: 9022, secret: 'cymru'});
srf.on('connect', (hostport) => {
  console.log(`connected to drachtio server offering sip endpoints: ${hostport}`);
})
.on('error', (err) => {
  console.error(`error connecting: ${err}`);
});

srf.invite((req, res) => {..});

srf.listen(opts)

Param	Type	Default	Description
opts	Object		listen options
[opts.host]	number	0.0.0.0	address to bind listening socket to
opts.port	number		tcp port to listen on
opts.secret	string		shared secret used to authenticate connections

listen for outbound connections from a drachtio server

Example

const Srf = require('drachtio-srf');
const srf = new Srf();

srf.listen({port: 3001, secret: 'cymru'});

srf.invite((req, res) => {..});

srf.endSession(msg)

Param	Type	Description
msg	req | res	SIP request or response object

terminate the tcp socket connection associated with the request or response object, if the underlying socket was established as part of an outbound connection. If the underlying socket was established as part of an inbound connection, this method call is a no-op (does nothing).

Example

const Srf = require('drachtio-srf');
const srf = new Srf();

srf.listen({port: 3001, secret: 'cymru'});

srf.invite((req, res) => {
  srf.createUas(req, res, {localSdp: mySdp})
    .then((uas) => {
      uas.on('destroy', () => {
        console.log('caller hung up');
        srf.endSession(req);
      });
    });
});

"connect" (err, hostport)

Param	Type	Description
err	Error	error encountered when attempting to authorize after connecting
hostport	Array	an Array of SIP endpoints that the connected drachtio server is listening on for incoming SIP messages. The format of each endpoint is protcocol/adress:port.

a connect event is emitted by an Srf instance when a connect method completes with either success or failure

"error" (err)

Param	Type	Description
err	Error	specific error information

an error event is emitted by an Srf instance when an inbound connection is lost

"cdr:attempt" (source, time, msg)

Param	Type	Description
source	String	'network'	'application', depending on whether the INVITE is \inbound (received), or outbound (sent), respectively
time	String	the time (UTC) recorded by the SIP stack corresponding to the attempt
msg	Object	the actual message that was sent or received

a cdr:attempt event is emitted by an Srf instance when a call attempt has been received (inbound) or initiated (outbound)

"cdr:start" (source, time, role, msg)

Param	Type	Description
source	String	'network'	'application', depending on whether the INVITE is inbound (received), or outbound (sent), respectively
time	String	the time (UTC) recorded by the SIP stack corresponding to the attempt
role	String	'uac'	'uas'	'uac-proxy'	'uas-proxy' indicating whether the application is acting as a user agent client, user agent server, proxy (sending message), or proxy (receiving message) for this cdr
msg	Object	the actual message that was sent or received

a cdr:start event is emitted by an Srf instance when a call attempt has been connected successfully

"cdr:stop" (source, time, reason, msg)

Param	Type	Description
source	String	'network'	'application', depending on whether the INVITE is inbound (received), or outbound (sent), respectively
time	String	the time (UTC) recorded by the SIP stack corresponding to the attempt
reason	String	the reason the call was ended
msg	Object	the actual message that was sent or received

a cdr:stop event is emitted by an Srf instance when a connected call has ended

Srf.Dialog

a SIP Dialog

Srf.SipError

inherits from Error and represents a non-success final SIP response to a request; status and reason properties provide the numeric sip status code and the reason for the failure.

Srf.parseUri

parses a SIP uri string

Returns: function - a function that takes a SIP uri and returns an object
Example

const Srf = require('drachtio-srf');
const srf = new Srf();
const parseUri = Srf.parseUri;

// connect, etc..

srf.invite((req, res) => {
 const uri = parseUri(req.get('From'));
 console.log(`parsed From header: ${JSON.stringify(uri)}`);
 // {
 //   "scheme": "sip",
 //   "family": "ipv4",
 //   "user": "+15083084807",
 //   "host": "192.168.1.100",
 //   "port": 5080,
 //   "params": {
 //      "tag": "3yid87"
 //    }
 // }
});

Dialog

Extends: EventEmitter
Class representing a SIP Dialog.

Note that instances of this class are not created directly by your code; rather they are returned from the Srf#createUAC, Srf#createUAC, and Srf#createB2BUA

• Dialog

  • new Dialog(srf, type, opts)

  • .sip

  • .local

  • .remote

  • .destroy([opts], [callback])

  • .modify(sdp, [callback])

  • .request([opts], [callback])

  • "destroy" (msg)

  • "modify" (req, res)

  • "refresh" (msg)

  • "info" (req, res)

  • "notify" (req, res)

  • "options" (req, res)

  • "update" (req, res)

  • "refer" (req, res)

  • "message" (req, res)

new Dialog(srf, type, opts)

Param	Type	Description
srf	Srf	Srf instance that created this dialog
type	string	type of SIP dialog: 'uac', or 'uas'
opts	Dialog~Options

Constructor that is called internally by Srf when generating a Dialog instance.

dialog.sip

Properties

Name	Type	Description
callId	String	SIP Call-ID
localTag	String	tag generated by local side of the Dialog
remoteTag	String	tag generated by the remote side of the Dialog

sip properties that uniquely identify this Dialog

dialog.local

Properties

Name	Type	Description
uri	String	sip
sdp	String	session description protocol

local side of the Dialog

dialog.remote

Properties

Name	Type	Description
uri	String	sip
sdp	String	session description protocol

remote side of the Dialog

dialog.destroy([opts], [callback])

Param	Type	Description
[opts]	Object	configuration options
[opts.headers]	Object	SIP headers to add to the outgoing BYE or NOTIFY
[callback]	function	if provided, callback with signature (err, msg) that provides the BYE or NOTIFY message that was sent to terminate the dialog

destroy the sip dialog by generating a BYE request (in the case of INVITE dialog), or NOTIFY (in the case of SUBSCRIBE)

Returns: Promise | Dialog - if no callback is supplied, otherwise a reference to the Dialog

dialog.modify(sdp, [callback])

Param	Type	Description
sdp	string	'hold', 'unhold', or a session description protocol
[callback]	function	callback invoked with signature (err) when operation has completed

modify the dialog session by changing attributes of the media connection

Returns: Promise | Dialog - if no callback is supplied, otherwise the function returns a reference to the Dialog

dialog.request([opts], [callback])

Param	Type	Description
[opts]	Object
opts.method	string	SIP method to use for the request
[opts.headers]	Object	SIP headers to apply to the request
[opts.body]	string	body of the SIP request
[callback]	function	callback invoked with signature (err, req) when operation has completed

send a request within a dialog. Note that you may also call request.info(..) as a shortcut to send an INFO message, request.notify(..) to send a NOTIFY, etc..

Returns: Promise | Dialog - if no callback is supplied a Promise that resolves to the response received, otherwise the function returns a reference to the Dialog

"destroy" (msg)

Param	Type	Description
msg	Object	incoming BYE request message

a destroy event is triggered when the Dialog is torn down from the far end

"modify" (req, res)

Param	Type	Description
req	Object	drachtio request object
res	Object	drachtio response object

a modify event is triggered when the far end modifies the session by sending a re-INVITE. When an application adds a handler for this event it must generate the SIP response by calling res.send on the provided drachtio response object. When no handler is found for this event a 200 OK with the current local SDP will be automatically generated.

"refresh" (msg)

Param	Type	Description
msg	Object	incoming re-INVITE request message

a refresh event is triggered when the far end sends a session refresh. There is no need for the application to respond to this event; this is purely a notification.

"info" (req, res)

Param	Type	Description
req	Object	drachtio request object
res	Object	drachtio response object

an info event is triggered when the far end sends an INFO message. When an application adds a handler for this event it must generate the SIP response by calling res.send on the provided drachtio response object. When no handler is found for this event a 200 OK will be automatically generated.

"notify" (req, res)

Param	Type	Description
req	Object	drachtio request object
res	Object	drachtio response object

a notify event is triggered when the far end sends a NOTIFY message. When an application adds a handler for this event it must generate the SIP response by calling res.send on the provided drachtio response object. When no handler is found for this event a 200 OK will be automatically generated.

"options" (req, res)

Param	Type	Description
req	Object	drachtio request object
res	Object	drachtio response object

an options event is triggered when the far end sends an OPTIONS message. When an application adds a handler for this event it must generate the SIP response by calling res.send on the provided drachtio response object. When no handler is found for this event a 200 OK will be automatically generated.

"update" (req, res)

Param	Type	Description
req	Object	drachtio request object
res	Object	drachtio response object

an update event is triggered when the far end sends an UPDATE message. When an application adds a handler for this event it must generate the SIP response by calling res.send on the provided drachtio response object. When no handler is found for this event a 200 OK will be automatically generated.

"refer" (req, res)

Param	Type	Description
req	Object	drachtio request object
res	Object	drachtio response object

a refer event is triggered when the far end sends a REFER message. When an application adds a handler for this event it must generate the SIP response by calling res.send on the provided drachtio response object. When no handler is found for this event a 200 OK will be automatically generated.

"message" (req, res)

Param	Type	Description
req	Object	drachtio request object
res	Object	drachtio response object

a message event is triggered when the far end sends a MESSAGE message. When an application adds a handler for this event it must generate the SIP response by calling res.send on the provided drachtio response object. When no handler is found for this event a 200 OK will be automatically generated.

SipError

Extends: Error
Class representing a SIP non-success response to a transaction

new SipError(status, [reason])

Param	Type	Description
status	number	SIP final status
[reason]	string	reason for failure; if not provided the standard reason associated with the provided SIP status is used

Create a SipError object

createServer()

Api: public
Create a new server.