Unused number hunter is Pyton based script to help you release (and save some $$$’s) on unused numbers that may be sitting in your Twilio account.
If you are in the habbit of buying Twlio numbers, using them for a project and then not relasing them this script will be the tool for you.

How to use:

  • Download the python script to a directory
  • Ensure you have the Twilio Python helper library installed, you can find this at: https://github.com/twilio/twilio-python
  • Edit the Accountsid, Authkey and number of call records you want to examine, saving the script.
  • Run: python /directory/NumberHunter.py

What will happen:

  • NumberHunter will grab all the phone numbers from your Twilio account, storing the numbers in a txt file called: TwilioNumbersInAccount.txt
  • NumberHunter will grab a copy of the call records up to the number (default is 100) you want to examine. (Saved in TwilioCallLog.txt)
  • NumberHunter will compare numbers in your call log against your Twilio numbers
  • NumberHunter will save a copy of your unused numbers in a file called unusedTwilioNumbers.txt
  • NumberHunter will ask you if you want to release these numbers – If you select Y it WILL REMOVE these numbers from your account immediately.

GitHub link: https://github.com/dotmat/TwilioPythonUnusedNumberHunter
Happy Hunting!

TL:DR : Python based script to search your account for unused numbers and release them.

In my last post: http://www.mathewjenkinson.co.uk/twilio-sms-conversations-using-cookies/ I used HTTP Cookies to ask multiple questions to a handset. This got me thinking, what if I could use that conversation to generate a lead in Salesforce.

For example, your at an event, ‘CloudForce’ for example 😉 and you want to ask your guests about the experience they are having as well as capture the guests phone number in a lead campaign in Salesforce ready to pick up with the lead after the event. This gives you instant feedback on how people are enjoying the event, an incoming lead stream and verified phone numbers from potential customers.

In this post, Im going to build on using Twilio cookies to populate a lead campaign in Salesforce. To initiate this setup, I want to get the interested lead to message a keyword “CloudForceEU” for example. Once the initial message comes in, I want to ask 4 questions to the lead and then pass the captured data to our Salesforce instance.

To replicate this setup you will need:

  • An account with Twilio (https://www.twilio.com/try-twilio)
  • A SMS capable number within your Account Portal.
  • A Salesforce instance where you can add custom lead fields and use Web2Lead Form generator
  • A PHP based server to host the script found on my Github.  – If your savy you can make your own in another language such as Ruby or Python 🙂

Setting up Salesforce

To begin we need to add 4 custom fields to our salesforce lead’s panel. As I am choosing to ask 4 questions to our potential lead I want to capture this information so I can get an overall feel for the event as well as capturing info about our potential lead.

To add a custom field in Salesforce go to : salesforce.com/p/setup/layout/LayoutFieldList?type=Lead&setupid=LeadFields

or:  Setup > Leads > Fields and scroll to the bottom for ‘Custom Fields’ It should look something like:

Leads Generation SalesForce

Leads Generation SalesForce

Here we want the button marked ‘New’. Following the steps, we want a new text box of no more than 150 (This is WAY more than we need as we are only gathering simple responses). Fill in the details for the new field and then continue along. I tend to add the details of the question in the description so that I know what Question1 relates to. Continue this until you have all your question fields added.

Now we are going to build our Web2Lead form and capture the ID’s needed for our SMS Script.

Navigate to: Customize > Leads > Web-To-Lead

Remove all the initial fields from the box marked ‘Selected Fields’ and then import:

  • PhoneNumber
  • Campaign
  • Question1
  • Question2
  • Question3
  • Question4

You could add first name to this setup but you would need add a name collection to the SMS conversation, while its easy to do. Its not something I will be doing in this setup.

In the end your setup should look something like:

SF Web2Lead

SF Web2Lead

Then click generate. Salesforce will spit you out some code that you could use in a webform but we are going to grab the details of this code and use it in our SMS lead tracker. The code will look something like:


<!– ———————————————————————- –>
<!– NOTE: Please add the following <META> element to your page <HEAD>. –>
<!– If necessary, please modify the charset parameter to specify the –>
<!– character set of your HTML page. –>
<!– ———————————————————————- –>

<META HTTP-EQUIV=”Content-type” CONTENT=”text/html; charset=UTF-8″>

<!– ———————————————————————- –>
<!– NOTE: Please add the following <FORM> element to your page. –>
<!– ———————————————————————- –>

<form action=”https://www.salesforce.com/servlet/servlet.WebToLead?encoding=UTF-8″ method=”POST”>

<input type=hidden name=”oid” value=”ABC123″>
<input type=hidden name=”retURL” value=”http://”>

<!– ———————————————————————- –>
<!– NOTE: These fields are optional debugging elements. Please uncomment –>
<!– these lines if you wish to test in debug mode. –>
<!– <input type=”hidden” name=”debug” value=1> –>
<!– <input type=”hidden” name=”debugEmail” –>
<!– value=”[email protected]”> –>
<!– ———————————————————————- –>

<label for=”phone”>Phone</label><input id=”phone” maxlength=”40″ name=”phone” size=”20″ type=”text” /><br>

<label for=”Campaign_ID”>Campaign</label><select id=”Campaign_ID” name=”Campaign_ID”><option value=””>–None–</option></select><br>

Question1:<input id=”Question1″ maxlength=”174″ name=”Question1″ size=”20″ type=”text” /><br>

Question2:<input id=”Question2″ maxlength=”174″ name=”Question2″ size=”20″ type=”text” /><br>

Question3:<input id=”Question3″ maxlength=”174″ name=”Question3″ size=”20″ type=”text” /><br>

Question4:<input id=”Question4″ maxlength=”174″ name=”Question4″ size=”20″ type=”text” /><br>

<input type=”submit” name=”submit”>



As you can see its quite comprehensive, what we need from this code snippet; is the form URL, formID and then the ID’s for our phone number, campaign and questions. From the script above we get

  • URL Endpoint: ‘https://www.salesforce.com/servlet/servlet.WebToLead?encoding=UTF-8’
  • FormID: ‘ABC123’
  • Phone Number: ‘phone’
  • Campaign ID : ‘Campaign_ID’
  • Question 1 : ‘Question1’
  • Question 2 : ‘Question2’
  • Question 3 : ‘Question3’
  • Question 4 : ‘Question4’

This is the data we need to plug into our SMS cookie script.

At the end of the Twilio SMS conversation, the script will bundle up the details of the conversation and HTTPS POST to the salesforce URL.

Using Twilio cookies to mange the SMS Conversation

In the last post: http://www.mathewjenkinson.co.uk/twilio-sms-conversations-using-cookies/ I used HTTP Cookies to ask multiple questions to a handset. Now we are going to do the same thing, except at the end of this conversation we are going to post the data to Salesforce. You can find a copy of the script on my Github Twilio 2 SalesforceLeads.

The full script Im going to use is:

// Load the questions we want:
$question1 = ‘Hello. Welcome to the event! We would like to ask you some questions about your experience.</Message><Message>What did you think of the venue & refreshments? 5 (Exceptional) 0 (Poor)’; // by adding the </Message><Message> you can break up the initial response into a welcome message and then question1.
$question2 = ‘And the content of the Presentations? 5 (Exceptional) 0 (Poor)’;
$question3 = ‘How likely are you to attend future Twilio events from 5 (Definitely would) to 0 (definitely would not)’;
$question4 = ‘Is there anything specific you would like to discuss with Twilio? 5 (Yes, please asks someone to call) 0 (I’ll contact you if I need anything)’;
// After we have all 4 questions we can upload to the DB and thank the user for their input
$endStatement = ‘Thanks for your time. Hope you have a fun day!’;

// If we have no cookies we need to set all the cookies to nil and ask the opening question.
if(!isset($_COOKIE[‘question1’])) {
$TwiMLResponse = $question1;
//setcookie(‘question1’, ‘nil’);
setcookie(‘event’, $_POST[‘Body’]);
setcookie(‘question1’, ‘nil’);
setcookie(‘question2’, ‘nil’);
setcookie(‘question3’, ‘nil’);
setcookie(‘question4’, ‘nil’);
// If Question 1 is blank we can pair the answer to question 1
elseif ($_COOKIE[‘question1’] == ‘nil’) {
setcookie(‘question1’, $_POST[‘Body’]);
$TwiMLResponse = $question2;
// If Question 1 is not blank we find out if question 2 is blank and move up the ladder
elseif (($_COOKIE[‘question2’] == ‘nil’)) {
setcookie(‘question2’, $_POST[‘Body’]);
$TwiMLResponse = $question3;
elseif (($_COOKIE[‘question3’] == ‘nil’)) {
setcookie(‘question3’, $_POST[‘Body’]);
$TwiMLResponse = $question4;
// After we get the response for question 4, we can assign it to the question.
// Now we have all 4 questions answered and can pass the thank you note and also make a HTTP POST to our end point
elseif (($_COOKIE[‘question4’] == ‘nil’)) {
// With the last question answered, we can reply with our end statement and POST all the data from the conversation.
$TwiMLResponse = $endStatement;
// So now we have the cookies for the event and questions 1 to 3 and the BODY tag for answer 4. Now we can make a POST request to our form with that data.

// Get cURL resource
$curl = curl_init();
// Set some options – we are passing in a useragent too here
curl_setopt_array($curl, array(
CURLOPT_URL => ‘https://www.salesforce.com/servlet/servlet.WebToLead?encoding=UTF-8’,
// POST fields for salesforce input:
CURLOPT_POSTFIELDS => array(‘oid’ => ‘ABC123’, ‘phone’ => $_POST[‘From’], ‘Campaign_ID’ => $_COOKIE[‘event’], ‘Question1’ => $_COOKIE[‘question1’], ‘Question2’ => $_COOKIE[‘question2’], ‘Question3’ => $_COOKIE[‘question3’], ‘Question4’ => $_POST[‘Body’])

// Send the request & save response to $resp
$resp = curl_exec($curl);
// Close request to clear up some resources
header(‘content-type: text/xml’);
<Response><Message><?php echo $TwiMLResponse; ?></Message></Response>

As you can see Im only use one script to manage the conversation, updating the cookies and working out where the data needs to be updated to and eventually POSTed too. As we are capturing questions about our SalesForceEU event Im going to need 4 questions:

$question1 = ‘Hello. Welcome to the event! We would like to ask you some questions about your experience.</Message><Message>What did you think of the venue & refreshments? 5 (Exceptional) 0 (Poor)’; // by adding the </Message><Message> you can break up the initial response into a welcome message and then question1.
$question2 = ‘And the content of the Presentations? 5 (Exceptional) 0 (Poor)’;
$question3 = ‘How likely are you to attend future Twilio events from 5 (Definitely would) to 0 (definitely would not)’;
$question4 = ‘Is there anything specific you would like to discuss with Twilio? 5 (Yes, please asks someone to call) 0 (I’ll contact you if I need anything)’;

As the script gets more replies from Twilio it populates the questions cookies until they are all full of data. Then we thank the user for their time, assemble the POST request and send it off to SalesForce.

CURLOPT_URL => ‘https://www.salesforce.com/servlet/servlet.WebToLead?encoding=UTF-8’,
// POST fields for salesforce input:
CURLOPT_POSTFIELDS => array(‘oid’ => ‘ABC123’, ‘phone’ => $_POST[‘From’], ‘Campaign_ID’ => $_COOKIE[‘event’], ‘Question1’ => $_COOKIE[‘question1’], ‘Question2’ => $_COOKIE[‘question2’], ‘Question3’ => $_COOKIE[‘question3’], ‘Question4’ => $_POST[‘Body’])

If we run a test between my phone and Salesforce we get:




and in SalesForce:

SalesForce Leed Capture from SMS

SalesForce Leed Capture from SMS


As you can see this opens up lots of possibilities of lead capture and accurate number sourcing from events. You can even have a campaign manager back at HQ reaching back out to leads while they are still at the event.


Working in support, I field a lot of queries from small business managers and startups about how to setup and build a phone menu system (IVR).

Interactive Voice Response (IVR) adds a level of class to your small business setup, they can make your organisation look bigger than it is and allows you to directly manage the routing of calls made to your company.

One of the best features of a Twilio based IVR is that you can give your customers one phone number and then route the calls to your sales / technicians / whoever as you need to.

–       No more ring this number for sales, ring this number for support etc.…

Lets propose we need to make an IVR for ‘John Smith Widget Company’, this IVR needs to have two menu options; one for sales and one for support and greet the caller with the office hours: 8am to 6pm


– When the caller selects an option (Sales or Support) we want to be able to route this call to an appropriate phone number (the companies sales manger for example), when this person (sales manager) answers the phone we want to be able to whisper that this is a sales call and offer them a chance to accept or reject the call.


– Should no one answer the phone or the call be rejected, as a fall back we need to explain to the caller no one is around and to leave a message on our voicemail system.

For this we will need:

A Twilio Account

A Twilio phone number

A webserver that supports a scripting language, I’m using PHP here but the code and logic will translate across most other languages.

If you haven’t done so already, sign up at https://www.twilio.com/try-twilio

You will need to verify your phone number and once in, copy your phone number, Accountsid and Authkey from your account portal page.

Download the Twilio PHP Libaray from github, the URL is:


Make a new directory, something called smbivr and copy the ‘Services’ into this directory.

Now we need a landing page for when someone calls your Twilio number.

Make a new file called twilioIncomingCallHandler.php and save it in your directory smbivr

In this file we are going to add:


// Phone Number for your Sales Line:

$salesNumber = “”;

// Phone Number for your Support line:

$supportNumber = “”;

// To set the Caller ID to be the actual caller, uncomment this:

//$callerID = $_GET[“From”];

// To set the CallerID to the number dialed IE your Sales Line uncomment this:

$callerID = $_GET[“To”];

// Check if the HTTP request is loop by checking for any pressed digits

$menuInput = $_GET[“Digits”];

// If the menu is 1 we know they want sales team so we are going to say

// ‘Transfering you to sales now, Please note call calls are recoreded for training purposes’

// Then we are going to call the sales line and whisper the details of the call as well as giving the agent to divert to VM.

// If the menu is 2 the call is for support, so are going to transfer the call to out support line and whisper that the call is about customer support.

// If the menu is blank its a 1st time caller so we great the caller and then present the landing menu.

if ($menuInput == “1”) {

$TwiMLResponse = “<Dial callerId=\””. $callerID . “\” timeout=\”18\” action=\”./handleDialCallStatus.php\”><Number url=\”./whisper.php?type=sales\”>$salesNumber</Number></Dial>”;


elseif ($menuInput == “2”) {

$TwiMLResponse = “<Dial callerId=\””. $callerID . “\” timeout=\”18\” action=\”./handleDialCallStatus.php\”><Number url=\”./whisper.php?type=support\”>$supportNumber</Number></Dial>”;


else {

$TwiMLResponse = “<Gather method=\”GET\” timeout=\”25\” numDigits=\”1\”><Say voice=\”alice\”>Hello and welcome to Chicken and Bee. Your partner for web, voice and messaging services. Our opening hours are 8 am to 6 PM London Time. For Sales please press 1. For support or other enquiries please press 2.</Say></Gather>”;


header(“content-type: text/xml”);


<Response><?php echo $TwiMLResponse; ?></Response>

As you can see from the code this file is going to do two things, the first time its called it will greet the caller with our welcome message, opening hours and then ask the caller who they would like to be directed too, when the user inputs a digit Twilio will make a HTTP POST to the same file but this time including the digit the caller pressed.

Now when the code runs, it will look for any digits pressed and provide a different set of TwiML instructions – in this case call either the sales or support line.

This is the normal for a IVR system, but we are going to branch off now and do some advanced bits.

For example what if the caller is a known customer or a high value customer, it might be a good idea for us to gather this callerID and check our CRM to see if they are in fact a customer.

When we made the <Dial> verb we also included some attributes, these included:




You can find more information on these verbs at:




The action URL (handleDialCallStatus.php) will handle the call when the dialed party has provided a response – hangup, voicemail etc.

The URL (whisper.php) will speak to the dialed party and give them an option to accept or decline the call based on some TwiML and scripting.

To make the ‘Number URL’ speak to the dialed party we direct the URL to a new script called ‘whisper.php’

In this file we are going to place:


// Find out what kind of whisper we are going to do is this a sales or support call?

$callType = $_GET[“type”];

// If the Type is a sales call say to the agent that this is a sales call and give them an option to divert to voicemail or accept the call.

if ($callType == “sales”) {

$TwiMLResponse = “<Gather action=\”./agentResponse.php\” numDigits=\”1\”><Say>You have an incoming sales call.</Say><Say>To accept the call, press 1.</Say><Say>To reject the call, press 2.</Say></Gather><Say>Sorry, I didn’t get your response.</Say><Redirect>screen-caller.xml</Redirect>”;


// If this is a support call say to the agent that this is a support call and give them an option to divert to VM or accept the call

if ($callType == “support”) {

$TwiMLResponse = “<Gather action=\”./agentResponse.php\” numDigits=\”1\”><Say>You have an incoming support call.</Say><Say>To accept the call, press 1.</Say><Say>To reject the call, press 2.</Say></Gather><Say>Sorry, I didn’t get your response.</Say><Redirect>screen-caller.xml</Redirect>”;


header(“content-type: text/xml”);


<Response><?php echo $TwiMLResponse; ?></Response>

As you can see from the code, we are passing the type of call: Sales or Support as a variable to this TwiML.

You could if you had a CRM such as Salesforce or vTiger make an API call to the database, querying if the callerID is a known customer and if so pass back details to be relayed to the dialed party – How fantastic would it be to have your CRM provide your agent with the call details before they even connect with the customer.

However, in this example we are going to pass just the message that someone has called the sales or support line and would they like to accept or decline the call.

If the user presses 1, then the call connects both parties together, if the user presses 2 the call is hung up and the original caller is presented with a ‘I’m sorry, no one is available’ – This is where the Dial Action URL comes in to play.

Create a new PHP file called handleDialCallStatus.php

In this file place:


// If the call is due to be hung up be cause the whisper hung up, then we want to redirect the call to Voicemail and capture the Voicemail

$whisperStatus = $_POST[“DialCallStatus”];

if ($whisperStatus == “busy” or “no-answer” or “failed”) {

$TwiMLResponse = “<Say voice=\”alice\”>I am sorry. No one is around at the moment to take your call. Please leave your name and number and someone will get back to you shortly. Thank you!</Say><Record action=\”./handleRecording.php\” maxLength=\”60\” finishOnKey=\”*\” /><Say>I did not receive a recording</Say>”;




$TwiMLResponse = “<Hangup/>”;


header(“content-type: text/xml”);


<Response><?php echo $TwiMLResponse; ?></Response>

This file will work out what happened with our called party. Did they hang up, was the line busy or did the call fail for some reason.

In the event that the any of these three events happen (Reject call, no answer or line busy) we can apologize to the caller and ask them to leave a voicemail.

In this file you can see that we are calling the Record verb, for more information on this please see:


Inside the record verb we are going to reference handleRecording.php  which is going to be the file responsible for generating the email we are going to send once the recording has been completed.

Our final file:  handleRecording.php is the file responsible for picking up the URL of the voicemail file and then do something with it. In this case its going to email me a copy of the recording. However you could put this URL (or file) in to a database or some kind of messaging alert.

The code is:


// Define Email Address and Name

$eMailAddress = “[email protected]”;

$emailName = “YourName”;

$phoneLineName = “Sales HotLine”; // The Name of the phone line called EG is this your Sales Hotline

// Get the details of the call and recording

$recordingURL = $_POST[“RecordingUrl”];

$fromCallerID = $_POST[“From”];

// Get the Time

$humanTime = date(‘H:i d/F’, time());

// Assemble the headers

$headers = “From: Voicemail<[email protected]>\r\n”; //Your Voicemail email address

$headers .= “MIME-Version: 1.0\r\n”;

$headers .= “Content-Type: text/html; charset=ISO-8859-1\r\n”;

// Assemble the MessageBody.

$eMailBody = “Hi $emailName,<br /><br />”;

$eMailBody .= “The $phoneLineName was Called today at: $humanTime<br />”;

$eMailBody .= “The Caller ID was: $fromCallerID<br />”;

$eMailBody .= “The Voicemail is: <br /><br /><audio controls><source src=\”” . $recordingURL. “\”></audio><br /><br />”;

$eMailBody .= “<a href=\”$recordingURL\”>Click here To listen</a><br />”;

$eMailBody .= “Thanks!<br /><br />Voicemail!”;

// Assemble the Mail message

// mail(to,subject,message,headers,parameters);

mail($eMailAddress, “New Voicemail for $phoneLineName”, $eMailBody, $headers);

header(“content-type: text/xml”);



You will need to amend all the bits of this file to fit your network / mail server, including FROM email address, TO email address, your name.

Once you have this setup your good to go!

Now when someone calls your Twilio number:

twilioIncomingCallHander.php will pick up the file, greet the caller and ask them where to direct the call.

When the user selects an option the caller will be played ‘ringing’ sound while Twilio rings the provided number, informs them that a caller is on the line and gives them an option to accept or reject the call.

If the person answering the call accepts the call, we connect both parties together.

If the person answering rejects the call or the call cant be connected, we divert the caller to an answer machine, take a message and then email the message to  an email address.

With this IVR you can add routes and direct calls between your departments quickly and easily.

Following on my expansion into telephony posts (See a previous one, on making FreePBX work with Twilio). A lot of people have been asking me to provide more information on how to make your phone say things or play and MP3 file.  In particular while in a conference room…

Lets break this down into two parts; Making ‘Say or Play Bots’ and then adding our ‘Say or Play Bot’ to a conference and doing something.

Making a ‘Say or Play Bot’

Using Twilio there are lots of ways to make an automated voice say something to a caller / listener;

Twimlet Message (https://www.twilio.com/labs/twimlets/message) Static Message or MP3 file
TwimelBin (http://twimlbin.com) Static Message
Static XML hosted on your webserver Static Message
Dynamic web script that generates custom Say XML hosted on your webserver Dynamic Message
Dynamic web script that plays a custom message pending some criteria Dynamic Message

Twimlet Message:

In this example we are going to use a Twimlet message to say “Hi, This is you’re 9 AM Meeting Reminder, The current time is 8.55 AM. You have a meeting with Bob in 5 minutes.”

The message could be anything, in this case I’ve choose to use a meeting reminder message. If you follow the URL: https://www.twilio.com/labs/twimlets/message You can input your message into the Twimlet generator and it will spit out the URL you need to use with Twilio to get your message spoken:


As you can see our message has now been encoded into a URL form, the spaces between words have been filled in with %20 if we were to buy a phone number now and use this in the Voice URL we would hear this message.


Twimelbin is an external tool that you can use to test writing your TwiML (XML) writing skills.  It will validate your TwiML and ensure that the syntax is correct, you can then use the URL link provided to reference this TwiML in your Twilio account.  In this example I’m going to copy and paste my TwiML here so you can see what the structure looks like:

<?xml version=”1.0″ encoding=”UTF-8″?>
<Say>Hi Caller.</Say>
<Say>I’m just in the shower at the moment</Say>
<Say>Please let me wash my hair in peace and I will call you back later today</Say>

Here you can see I have linked lots of ‘Say’ commands together in one response. We could if we wanted to be annoying (if!) get each command to be spoken in a different voice or even language (https://www.twilio.com/docs/api/twiml/say) but ill skip that for now.

When your finished composing your Twimelbin entry you take the URL at the top of the page and use this to look up your TwiML in your phone number URL.

Static XML hosted on your own machine:

Static XML and a Twimelbin response are exactly the same, the only difference that one is hosted on your platform and one is hosted by Twimelbin. There are benefits to both; I won’t go into the merits of self hosting vs a 3rd party for any kind of HTTP activity here.

Dynamically generated TwiML response: 

This is where is gets fun! With a dynamic script we can make our message be customised to the caller, the time of day, the weather or any other factor we want! Lets say for example that we have two callers; Mathew and Steve. Mathew’s number is +44123456 and Steve’s is: +44987654 as we are generating this response on demand we can input these names into the <Say> response and give the caller a more personal response.

In this example I’m using PHP, but you could easily use another web language.


$people = array(

// if the caller is known, then greet them by name
if(!$name = $people[$_REQUEST[‘From’]]) $name = “Caller”;

// now greet the caller
header(“content-type: text/xml”);
echo “<?xml version=\”1.0\” encoding=\”UTF-8\”?>\n”;
<Say>Hello <?php echo $name ?>.</Say>

In this example, I made an array of data – mine and Steve’s number and then used the array to look up the name, if either Steve or I called the Twilio number from those numbers it would say Hi ‘Steve / Mathew’ if none of the numbers were recognised the caller would be just greater as just a ‘Hello Caller’

You can use the same kind of dynamic scripting language to play specific files, this could be to either specific times of the day, caller ID’s or special events.

I won’t go into the code here but the basic set up is:

IF event is true

Do this

Else (if not true)

Do this

So for example:

If time = before 12

Play the morning MP3 file

Else (If not true)

Play the Afternoon MP3 file

an example of this in PHP would be:


if (date(‘H’) < 12) {
$mp3_file =”http://domain.com/afternoon_mp3.mp3″;

// Play the AM / PM file to the caller
header(“content-type: text/xml”);
echo “<?xml version=\”1.0\” encoding=\”UTF-8\”?>\n”;
<Play><?php echo $mp3_file; ?></Play>

When this script is called it will check the time, if the clock is before 12 it will fetch the morning MP3 file and if its in the afternoon  it will fetch the afternoon mp3 file. You could go one step further and make an evening file. But for this setup lets assume an morning and afternoon setup 🙂

So whats a bot?

In simple terms a bot is a program / application that just does one thing. In the use case here you could have a phone bot that people could ring and it would recite company open hours.




This Twimlet just informs the callers of the times, Mathew’s superstore will be open.


So more recently I have been playing around with cloud technologies, namely building a cloud based hosting platform to replace an ageing home-based server solution. Don’t get me wrong my little Mac Mini server has been phenomenal, but the more recent releases of Mac OS X Server have left me wanting a bit more control and a bit less hardware.

Enter Digital Ocean (shameless referral plug: https://www.digitalocean.com/?refcode=8dc34df963c1 ) who allow you to build a very quick virtual machine capable of handling mail, HTTP and other web service based systems (that I have now retired and / or moved to the cloud).

One of the more recent projects I have wanted to build is a private branch exchange (PBX (Phone network)) so that I can adopt a singular 1 number per country approach, i.e. have a US based number that people can call and SMS, a UK based number that people can call and SMS, etc. This would save giving people a whole lot of different numbers – when Im in the UK ring a local uk number when I’m in the US ring a local us number..

Following lots of sniffing around for how to install PBX software onto a hosted platform I stumbled across this document: https://www.digitalocean.com/community/articles/how-to-install-freepbx-on-centos-6-4

I’m not going to copy and paste the guide word for word as its fairly self explanatory. If you have any problems following the guide, check out the comments at the bottom of the page as they helped.

From here we need to configure three things; Trunks (Calling in and Out), Extensions (Phones to answer the calls) and Routing (What calls go where based on logic).

First lets get extensions setup, its the quickest way to test your PBX is working correctly.

Navigate to your server and login to the FreePBX login it should be something like: YOURDOMAIN.com/admin/config.php

From here you want ‘Applications’ drop down menu and then ‘Extensions’

We are going to add 2 SIP based devices so select the option for ‘Generic SIP Device’ and then click submit.

As this is a private PBX I don’t foresee needing a lot of numbers, however a good organisational setup is still good idea. – Don’t go charging ahead into making your first extension ‘1’ and your second extension ‘2’.

I use the two hundred block for all my extensions, IE the first extension is 201 and the second extension is 202. As I need to add more extensions to the PBX they will become 203, 204, 205, etc.

The three main values we need to set here, are the user extension, Display Name and secret (password).  If you follow my convention you should setup ‘201’, ‘Mathew’ and ‘mysupersecretpassword’. Once you have setup your first user, do the same again so you have a second user (appending the next extension, username and password).  – Now we can test our PBX. If you have an iPhone – I recommend downloading any of the open VOIP Clients, my fav is ‘LinPhone‘. Its simple, easy to use and you can turn on the debugger if you need to.

If you have more than 1 phone you can download Linphone to that as well (Or another VOIP client) and try to ring each other. Or if you have 1 phone and your computer look at downloading x-lite (X-Lite)

To ring another IP phone on your PBX just punch in the extension number, 202 to ring the second phone from the first and 201 to ring the first phone from the second.

Once you have established that your phones are working we can begin to get calls into the PBX from the outside world.

Inbound Calling

First we need to organise inbound calling from Twilio.

Head over to Twilio.com and sign up for a trial account, you will need an email address and a mobile / cell phone to validate yourself against. Once you signed up you will need to provision a telephone number, you can do this in your account at: https://www.twilio.com/user/account/phone-numbers/available/local

Next we need to configure what we want to happen with that number when someone calls it, as Twilio uses TWiML (an extremely well documented type of XML) we can set Twillio to make a sip call to our PBX and connect the call over. On a hosted platform place a new xml document. Something like: www.yourdomain.com/twilio.xml

Our XML needs to look like this:

<?xml version=”1.0″ encoding=”UTF-8″?>
<Sip>sip:[email protected]</Sip>

We can also use a Twimlet to perform the same thing (except it doesn’t look as nice as the above XML:


As you can see, the XML very easy to read, should anyone now dial our newly provisioned number, Twilio will transfer the call to our 201 extension on the PBX. (Almost – we have a bit more setup to do first!).

Login to your PBX via a root terminal and navigate to /etc/asterisk/ by typing

cd /etc/asterisk/

Here we need to edit the sip.conf by typing:

nano -w sip.conf

Here we are going to add all the known IP addresses of Twilio so that when one of the gateways makes a request to our PBX the PBX will answer the call and route it accordingly.

The SIP document held at: https://www.twilio.com/docs/sip contains the list of IP addresses used by Twilio for connections via SIP. To add them to sip.conf we need to add the following to the document:

context = fromtwilio
type = peer

























Save the file and now either reboot asterisk or the server. As the server takes seconds to reboot I tend to follow the save command with just

Sudo reboot

which reboots the whole thing, as this server is for my own use; I’m less worried about the number of users who I will be kicking off when I do this.

Once your back up and working again, if you navigate to: FreePBX system status, it should tell you that 20+ gateways are online. With your backup phone or laptop logged in as your SIP extension we set the look up (201 in the above case) you should be able to call your number and your VOIP phone should ring! (Take 5 mins to strut around the room looking proud and ring yourself a few times!)

Outbound Calling: 

Outbound calling allows you to make call from your VOIP client via your PBX to the real world using Twilio as the gateway. In short we are going to get Twilio to connect the VOIP client to the rest of the world using the callerID we already provisioned.

There is a lot of reference material regarding SIP on the SIP Twilio Page (https://www.twilio.com/docs/sip/sending-sip-how-it-works)

The basics of it include, we need to make a SIP endpoint on Twilio, then when your SIP route references this endpoint, Twilio will make a URL request back to your server to get TwiML to decide what to do with the call.

Head over to: https://www.twilio.com/user/account/sip/domains and click the button ‘Create SIP Domain’

We need to create a Twilio SIP domain, pick something nice and unique such as mypbxservername  – Twilio will append .sip.twilio.com onto this so you will end up with a complete string that looks like this: mypbxservername.sip.twilio.com

Next we need to give it a friendly name, this is just so you can remember what it’s called.

In voice URL, please fill in:


This will give us a nice uncomplicated message, indicating our success from going from FreePBX to Twilio.

Next we need to generate a way to protect our SIP endpoint.  As Im using a static IP server I can add this to a white list. Click ‘CreateIP Access Control List’ and a new drop down will appear. Here we want to add the IP address of our server and then give it a friendly name.

Save all the changes and then save the domain to Twilio.

Move over to your FreePBX server and add a trunk in the usual fashion: Connectivity > Trunks. 

Here we need to make a new SIP Trunk; so click ‘Add SIP Trunk’

Call the Trunk something like ‘Twilio’ and then move down to the next trunk name (again, Twilio). In Peer details we need to add the three points:


Then click submit changes – Ignore an errors you get.

Then we need to add in outbound route, setting it so that when we dial a number on our extensions, FreePBX knows to route the call to our Twilio Trunk.

So, lets add a outbound route; Connectivity > Outbound Routes.

Here, I have set the route name to be ‘Twilio’, now scroll down to ‘Dial Patterns that will use this Route’. We need to configure the PBX so that when we dial a certain prefix, FreePBX will pick up this prefix, remove the prefix and then hand the call over to Twilio to be dialled and connected.

The window is broken up into three boxes, ‘Prepend’, ‘Prefix’ and ‘Match Pattern’. We do not need to worry about ‘Prepend’ so the next bit we need to add a dial prefix so that the PBX knows we want to use this route. I have chosen the prefix of 71, so if I wanted to dial a phone number of 1 415123 1234 I would dial 7114151231234. Here FreePBX will pick up the 71, remove those digits from the string and then hand the 14151231234 to Twilio for dialling. The last part ‘match pattern’ is used to match we have the right numbers dialled. For example in the US, a long distance number would be 1-415-123-1234 so the match pattern would be 1XXXXXXXXXX as we only want +1 numbers to be routed this way. You could also narrow this down do only a certain area code could be called by doing this: 1901XXXXXXX – where 901 is the area code only accepted.

To dial the UK on this dial pattern you would need to setup: 44XXXXXXXXXX, again if you wanted to setup only landlines you could do: 441XXXXXXXXX and 442XXXXXXXXX which would limit numbers to only 441 and 442 (as in 44 1895 and 44 208).

You should now be able to dial a real number from your PBX extensions and you should hear ‘Congratulations, You just Made your first call with Twilio SIP’. PERFECT! This means that your FreePBX box was able to hand over a call to Twilio, and Twilio was able to execute the message we predefined earlier!

Now we need to modify our Twilio URL so that it points to a file we can use to dial our actual end point. On an internet facing server create a new file called asterisk.PHP

to which we need to add:

<?xml version=”1.0″ encoding=”UTF-8″?>
<Dial callerId=”+YOURCALLERID”>
<Number><?php preg_match(‘/:([0-9]+)@/’, $_POST[‘To’], $matches); echo $matches[1]; ?></Number>

You need to append YOURCALLERID with a caller ID from your account, either a verified number or one of your Twilio numbers. This will be the caller ID used when your PBX dials out via Twilio.

Now take the internet facing location of this file. I’m going to assume: http://domain.com/asterisk.php  – Just update the URL location that was Twimlets message of congratulations with your URL. This should now setup your PBX so that when it makes a request to Twilio, Twilio looks up the URL and injects the TO number into the TwiML, followed up by dialling that number.

Tada!! That should be it! You should now be able to dial your PSTN number and have it call your PBX extensions and you should now be able to dial out from your PBX to PSTN lines using Twilio!