SIP trunk for Asterisk

Connecting your Asterisk server to a SIP trunk for incoming and outgoing calls can be done easily – and at a low cost – or even for free.

In this article we will go through how you can connect a SIP-trunk to your Asterisk server in a matter of minutes.

Step-by-step setup of SIP-trunk

You can have your new SIP trunk up and running in a few minutes – at zero cost – by following these steps:

1. Get a free Sonetel account
   You can sign up for a free account here.
2. Get a free phone number for testing
   On the phone numbers page you can select a free trial number, that allows you to test things a few days for free. If you install a free Business Messenger at your website, you can even have a number free forever.
3. Redirect incoming calls to your SIP address
   Configure your free trial number to send incoming calls to the SIP address of your Asterisk.
4. Send us your IPs for outbound calls
   Send the IP addresses of your SIP servers to support@sonetel.com so that we can whitelist them on our side for allowing your outbound calls.
5. Whitelist our IPs in your Asterisk
   Whitelist all Sonetel IP’s on your Asterisk phone system.
6. Set up your Asterisk
   Follow the steps in the next section to configure your Asterisk to receive and make calls via your new SIP trunk.

Configure your Asterisk server to use the SIP trunk

Follow the steps below to configure your Asterisk server to use your new SIP trunk.

1. pjsip.conf
   Add the following configuration to your pjsip.conf file (or copy it from this text file).

   [sip.sonetel.com]
   type=endpoint
   transport=transport-udp
   context=sonetel
   disallow=all
   allow=ulaw,alaw
   aors=sip.sonetel.com
   
   

[sip.sonetel.com]

type=aor qualify_frequency=60 contact=sip:sip.sonetel.com:5060

[sip.sonetel.com]

type=identify endpoint=sip.sonetel.com match=sip.sonetel.com

.

[1001]                   ; replace with a name or digits of your choice
type=friend
host=dynamic
secret=password          ;<password of your choice>
allow=ulaw,alaw
context=sonetel

[sonetel]
exten => _X.,1,NoOp(${EXTEN:1})
exten => _X.,n,Set(CALLERID(num)=+NUMBER
exten => _X.,n,Dial(SIP/${EXTEN}@sip.sonetel.com)

Things you can do next

If you are happy with your new SIP-trunk, you may consider taking additional steps.

• Add some funds to your prepaid account
  Charges for calls are deducted from your Sonetel prepaid account which can be refilled with credit card, PayPal and more.
• Add some more phone numbers
  You can get more phone numbers in your hometown or anywhere else worldwide, and connect them to your Asterisk via your SIP trunk. You can also port existing numbers to Sonetel.
• Set up an Avalanche message
  Consider preparing a message using the Voice apps, that can be played to callers in case your Asterisk server becomes unavailable at any point in time.
• Use the lower Intra-EU rates
  If you make calls to European countries, consider using the methods available for minimizing your cost for calls.