How to set up a SIP trunk with FreePBX and Twilio

FreePBX Server Requirements

• FreePBX 14.0
• Asterisk 13
• 1 Twilio Number
  Mine will be (579)123-1234

Notes:

• My setup is behind a router.
• The private (internal) IP address of my FreePBX server is 192.168.10.160.
• FreePBX by default uses port 5160 for chan_sip but I changed it to 5060.
• FreePBX by default uses ports from 10000 to 20000 for RTP but I changed them from 10000 to 10500.
• The public (external) IP address is 123.123.123.123.

Twilio Account Setup

Elastic SIP Trunking

General

Option	Value
TRUNK NAME	testing
Call Recording	No
Secure Trunking	Disabled

Termination

Option	Value
Termination URI	testing.pstn.twilio.com (Choose whatever you want)
IP Access Control Lists	Choose what IP will be granted to communicate with your trunk. In this tutorial I will use my public IP address: 123.123.123.123
Creditentiel Lists	Create a username and password that will be used to connect to our trunk later. In this tutorial I will use: Username: MY_USERNAME123 Password: MY_PASSWORD123

Origination

Option	Value
Origination SIP URI	sip:123.123.123.123
Priority	10
Weight	10

Numbers

Setting UP Outgoing Calls

Trunks

For now, we will need to create 1 truck for outgoing calls.

Let’s begin by creating a SIP trunk of type chan_sip.

General Tab

Option	Value
Trunk Name	twilio0
Hide CallerID	No
Outbound CallerID	+15791231234 (Twilio number in E.164 format)
CID Options	Allow Any CID (if your are using Twilio Trial, use Force Trunk CID)
Asterisk Trunk Dial Options	T

Dialed Number Manipulation Rules Tab

Preprend	Prefix	Match pattern
		+1579xxxxxxx (I will only accept calls to local numbers starting with +1579 and followed by 7 other numbers)

sip Settings

Outgoing

Option	Value
Trunk Name	twilio0
PEER Details	host=testing.pstn.twilio.com username=MY_USERNAME123 secret=MY_PASSWORD123 type=peer dtmfmode=rfc2833 canreinvite=no disallow=all allow=ulaw insecure=port,invite context=from-trunk nat=yes

Incoming

Leave empty

Outbound Routes

Route Settings

Option	Value
Route Name	PBX to Twilio Trunk (whatever you want it to be called)
Route Password	Set this only if you want this route to be password protected, so only a few users could use it.
Trunk Sequence for Matched Routes	twilio0

Dial Patterns

Preprend	Prefix	Match pattern	CallerID
		+1579xxxxxxx
+		1579xxxxxxx
+1		579xxxxxxx

That’s it! You should now be able to place outbound calls! We can now begin we the configuration of incoming calls.

Setting UP Incoming Calls

Trunks

For now, we will need to create 4 trucks for incoming calls.

Why do we need to create 4 trunks?
Because we have to create one for each Twilio’s IP addresses.

I used NORTH AMERICA VIRGINIA Twilio’s IP addresses:
54.172.60.0, 54.172.60.1, 54.172.60.2 and 54.172.60.3
https://www.twilio.com/console/sip-trunking/your-network

Let’s begin by creating an SIP trunk of type chan_sip and you will have to do the same for all other Twilio’s IP addresses.

General Tab

Option	Value
Trunk Name	twilio1
Hide CallerID	No
Outbound CallerID
CID Options	Allow Any CID
Asterisk Trunk Dial Options	T

sip Settings

Outgoing

Option	Value
Trunk Name	twilio1
PEER Details

Incoming

Option	Value
USER Context	twilioin1
USER Details	host=54.172.60.0 (first Twilio’s IP) type=peer insecure=port,invite canreinivite=no

Follow the routine for the next three IP addresses.

Inbound Routes

General Tab

Option	Value
Description	Twilio Trunk to PBX
Set Destination	Choose where you want inbound calls to be routed in your PBX server. You could route them to a group of extensions (All Desks) or one extension (Office Desk).

You should now be able to receive calls!

Common Problems

Remote extension can’t register:

• Verify that your ports are opened (5060, 10000-10500) on the server.
• Verify that your client have opened port 5060.
• Try to change the remote extension “nat option” to yes in the Extension module from Applications menu.