diff --git a/lib/Subscribe.d.ts b/lib/Subscribe.d.ts
new file mode 100644
index 000000000..d2a353ff3
--- /dev/null
+++ b/lib/Subscribe.d.ts
@@ -0,0 +1,23 @@
+/// <reference types="node" />
+import {EventEmitter} from 'events'
+
+import {ExtraHeaders, Originator, OutgoingListener, SessionDirection, TerminateOptions} from './RTCSession'
+import {IncomingResponse} from './SIPMessage'
+import {NameAddrHeader} from './NameAddrHeader'
+import {causes} from './Constants';
+
+export interface AcceptOptions extends ExtraHeaders {
+  body?: string;
+}
+
+export interface SendSubscribeOptions extends ExtraHeaders {
+  contentType?: string;
+  eventHandlers?: Partial<MessageEventMap>;
+}
+
+export class Subscribe extends EventEmitter {
+
+  send(target: string, body: string, options?: SendSubscribeOptions): void;
+
+  on<T extends keyof MessageEventMap>(type: T, listener: MessageEventMap[T]): this;
+}
diff --git a/lib/Subscribe.js b/lib/Subscribe.js
new file mode 100644
index 000000000..5dba1ff7b
--- /dev/null
+++ b/lib/Subscribe.js
@@ -0,0 +1,156 @@
+const EventEmitter = require('events').EventEmitter;
+const Logger = require('./Logger');
+const JsSIP_C = require('./Constants');
+const SIPMessage = require('./SIPMessage');
+const Utils = require('./Utils');
+const RequestSender = require('./RequestSender');
+
+const logger = new Logger('Subscribe');
+
+module.exports = class Subscribe extends EventEmitter
+{
+  constructor(ua)
+  {
+    super();
+
+    this._ua = ua;
+    this._request = null;
+
+  }
+
+  send(target, body, options = {})
+  {
+    const originalTarget = target;
+
+    if (target === undefined || body === undefined)
+    {
+      throw new TypeError('Not enough arguments');
+    }
+
+    // Check target validity.
+    target = this._ua.normalizeTarget(target);
+    if (!target)
+    {
+      throw new TypeError(`Invalid target: ${originalTarget}`);
+    }
+
+    // Get call options.
+    const extraHeaders = Utils.cloneArray(options.extraHeaders);
+    const subscriptionDuration = options.subscriptionDuration || 1;
+    const contentType = options.contentType || 'text/plain';
+    const eventType = options.eventType;
+
+    extraHeaders.push(`Content-Type: ${contentType}`);
+    if (eventType === 'message-summary')
+    {
+      extraHeaders.push(`Contact: ${target}`);
+      extraHeaders.push(`Expires: ${subscriptionDuration}`);
+      extraHeaders.push(`Event: ${eventType}`);  
+    }
+
+    this._request = new SIPMessage.OutgoingRequest(
+      JsSIP_C.SUBSCRIBE, target, this._ua, null, extraHeaders);
+
+    if (body)
+    {
+      this._request.body = body;
+    }
+
+    const request_sender = new RequestSender(this._ua, this._request, {
+      onRequestTimeout : () =>
+      {
+        this._onRequestTimeout();
+      },
+      onTransportError : () =>
+      {
+        this._onTransportError();
+      },
+      onReceiveResponse : (response) =>
+      {
+        this._receiveResponse(response);
+      }
+    });
+
+    request_sender.send();
+  }
+
+  _receiveResponse(response)
+  {
+    if (this._closed)
+    {
+      return;
+    }
+    switch (true)
+    {
+      case /^1[0-9]{2}$/.test(response.status_code):
+        // Ignore provisional responses.
+        break;
+
+      case /^2[0-9]{2}$/.test(response.status_code):
+        this._succeeded('remote', response);
+        break;
+
+      default:
+      {
+        const cause = Utils.sipErrorCause(response.status_code);
+
+        this._failed('remote', response, cause);
+        break;
+      }
+    }
+  }
+
+  _onRequestTimeout()
+  {
+    if (this._closed)
+    {
+      return;
+    }
+    this._failed('system', null, JsSIP_C.causes.REQUEST_TIMEOUT);
+  }
+
+  _onTransportError()
+  {
+    if (this._closed)
+    {
+      return;
+    }
+    this._failed('system', null, JsSIP_C.causes.CONNECTION_ERROR);
+  }
+
+  _close()
+  {
+    this._closed = true;
+    this._ua.destroyMessage(this);
+  }
+
+
+  _failed(originator, response, cause)
+  {
+    logger.debug('SUBSCRIBE failed');
+
+    this._close();
+
+    logger.debug('emit "failed"');
+
+    this.emit('failed', {
+      originator,
+      response : response || null,
+      cause
+    });
+  }
+
+  _succeeded(originator, response)
+  {
+    logger.debug('SUBSCRIBEsucceeded');
+
+    this._close();
+
+    logger.debug('emit "succeeded"');
+
+    this.emit('succeeded', {
+      originator,
+      response
+    });
+  }
+};
diff --git a/lib/UA.js b/lib/UA.js
index fa26c2183..221dd98b5 100644
--- a/lib/UA.js
+++ b/lib/UA.js
@@ -4,6 +4,7 @@ const JsSIP_C = require('./Constants');
 const Registrator = require('./Registrator');
 const RTCSession = require('./RTCSession');
 const Message = require('./Message');
+const Subscribe = require('./Subscribe');
 const Options = require('./Options');
 const Transactions = require('./Transactions');
 const Transport = require('./Transport');
@@ -257,6 +258,27 @@ module.exports = class UA extends EventEmitter
     return message;
   }
 
+  /**
+   * Send a subscription.
+   *
+   * -param {String} target
+   * -param {String} body
+   * -param {Object} [options]
+   *
+   * -throws {TypeError}
+   *
+   */
+  sendSubscribe(target, body, options)
+  {
+    logger.debug('sendSubscribe()');
+
+    const subscribe = new Subscribe(this);
+
+    subscribe.send(target, body, options);
+
+    return subscribe;
+  }
+
   /**
    * Send a SIP OPTIONS.
    *
@@ -742,6 +764,15 @@ module.exports = class UA extends EventEmitter
         {
           session.receiveRequest(request);
         }
+        // RFC3842 - check for message waiting information
+        else if (request.event['event'] === 'message-summary') 
+        {
+          this.emit('sipEvent', {
+            event : request.event,
+            request
+          });
+          request.reply(200);
+        }
         else
         {
           logger.debug('received NOTIFY request for a non existent subscription');