About Asterisk

Asterisk is a free telephone Private Branch Exchange (PBX) system. This can most easily been seen as a telephone system used to connect callers and as a sort of answering and dispatching machine. (e.g. "press 1 to speak to ..." etc)

Connecting to existing systems

Connecting Asterisk to an existing telephone network. This is called a PSTN call (Public Switched Telephone Network) Asterisk can be connected to a SIP or IAX provider (like VoIPBuster) or by using a (voice-)modem-card of Zaptel-card in de Asterisk-server.

VoIPBuster

First you should create an account with VoIPBuster. This can be done in the VoIP-Buster-software. (Windows only) These login-data must later be entered in the Asterisk configuration. Using VoIPBuster, you can make calls for free, for at least 2 minutes, possibly longer.

After registering an account with VoIPBuster, you also receive an email with the accountinfo. (username, passwd)

• FreePBX - inloggen (maint/passwd)
• + Extensions aanmaken
• + Trunk aanmaken (VoIPbuster account invullen)
• + routing aanmaken (nummers die lijken op een bepaald patroon gaan via de route VoIPBuster)
• X-lite instellen

A few config-files have to be changed in order to get the system to work with VoIPBuster

Adding to sip.conf:

[voipbuster]
type=peer
host=sip1.voipbuster.com
username=GEBRUIKERSNAAM
secret=WACHTWOORD
notransfer=yes
insecure=very
externip=JEEXTERNEIP
context=voipbuster-out

register => GEBRUIKER:WACHTWOORD@sip1.voipbuster.com

More information on VoIPBuster homepage

At this point there is a (peer) connection active. The only thing left is making it work.

extensions.conf

[voipbuster-out]
exten => _0[12345789]XXXXXXXX,1,Dial,IAX2/voipbuster/0031${EXTEN:5}
exten => _0[12345789]XXXXXXXX,2,Congestion
exten => _XXXXXXX,1,Dial,IAX2/voipbuster/0031[b]35[/b]${EXTEN}
exten => _XXXXXXX,2,Congestion
[home]
exten => 7500,1,VoicemailMain
exten => 7500,2,Hangup
exten => 9999,1,Ringing
exten => 9999,2,Dial(SIP/9999,20,T)
exten => 9999,3,Voicemail(u9999)
exten => 9999,4,Hangup
include => voipbuster-out
exten => _06XXXXXXXX,1,Dial(SIP/${EXTEN}@pstn-spa3k,60,)
exten => _06XXXXXXXX,2,Congestion 

Previous code will operate as follows: All extensions of 10 digits, starting with a "0", will replace the leading zero with "0031" (Dutch country-code), which is needed for using VoIPbuster.

7500 is the voicemail

9999 is de incomming line, for Voipbuster-IN. At this moment, this does not yet work.

06 numbers are routed through the installed modem-card, because this is cheaper than using VoIPbuster.

Example of SIP.conf:

[9999]
type=friend
language=nl
host=dynamic
context=home
secret=WACHTWOORD
mailbox=9999
dtmfmode=rfc2833
disallow=all
allow=ulaw
[5555]
; If you're using Asterisk, this goes into the Incoming settings
; For your Trunk
type=friend
host=dynamic
; If using Asterisk@home, change the below line to context=from-internal
context=home
secret=WACHTWOORD
dtmfmode=rfc2833
disallow=all
allow=ulaw
insecure=very
[pstn-spa3k]
; If you're using Asterisk, this section goes into the Outgoing Settings
; for your trunk.
type=peer
auth=md5
host=134.145.134.18
port=5061
secret=WACHTWOORD
username=asterisk
fromuser=asterisk
dtmfmode=rfc2833
; If using Asterisk@home, change the below line to context=from-internal
context=home
insecure=very 

If all went well, it is now possible to make a call using VoIPBuster. Using a free account, the call is limited to 2 minutes.

It is also possible to get a telephone number with VoIPbuster. See their site for more info.

Links

• Het grote Asterisk topic op Tweakers