Using Multitel as your outbound call provider with plain Asterisk

In this tutorial we'll show you the settings you need to do to be able to call out via Multitel.

First of all, edit /etc/asterisk/sip.conf

Your file should look like this:

[multitel]
type=friend
host=term.multitel.net
dtmfmode=rfc2833
context=default ;or whatever context you use
canreinvite=no
allow=ulaw
allow=g729
insecure=port,invite
fromdomain=term.multitel.net

Then, please edit /etc/asterisk/extensions.conf:

Your file should look like this:

[outgoing]
exten => _X,1,Dial(SIP/${EXTEN}@multitel)
exten => _011.,1,Dial(SIP/${EXTEN:3}@multitel) ; strip 011 prefix , its not needed

Next, please make sure your IP address is authenticated to send calls to Multitel.

Please visit https://www.multitel.net/cp and click on the "Profile setting" link.

This will take you to this link: https://www.multitel.net/auth/setting

In the "Termination IPs" tab, please add your IP address:

If you need to use a FQDN instead of IP address, please make sure you are also specifying a Prefix and that you are actually sending the calls with that prefix as the system will try first to match your prefix and then do a DNS lookup for your FQDN to see if it matches the IP address you're sending calls from.

Also, if using a prefix, please make sure prefix ends in "#" as this will be the separation between prefix and number.

As an example, if you are using (for example) dyndns and your FQDN is johndoe.dyndns.net , you will be adding address "johndoe.dyndns.net" and whatever prefix you wish (say "123#")

You will then have to send calls as 123#18886868581 , if you were calling our office number . System will match the 123# prefix with your account and see if johndoe.dyndns.net matches the IP address you're sending calls from. If its a match, you'll be allowed to send calls. If not, your calls will be rejected.