Using the Pilmo Gold service with Asterisk

In this example setup I'll describe two things:
- how to connect Asterisk to the Pilmo Gold service
- how to configure Asterisk and iptables to be able to use their locked Voicefinder ATA
I've personally combined the two to allow incoming calls from Pilmo, while using cheaper providers for my outgoing calls.

In the examples 192.168.1.3 is the Voicefinder and 192.168.1.2 is the Asterisk server.

sip.conf

 [general]
 context=default 
 port=38383
 bindaddr=0.0.0.0
 srvlookup=no
 nat=no
 
 ;this registers with pilmo so we can receive calls
 register => 31201234567:yourpilmopassord@sip.ritstele.com:38383

 ;allow incoming calls from pilmo
 [212.26.192.155:38383]
 type=user
 insecure=yes
 context=incoming
 disallow=all
 allow=g729
 ;allow incoming calls from pilmo2/bbned
 [212.26.192.153:38383]
 type=user
 insecure=yes
 context=incoming
 disallow=all
 allow=g729

 ;outgoing calls to pilmo
 [pilmo]
 type=peer
 user=phone
 usereqphone=yes
 username=31201234567
 secret=yourpilmopassword
 insecure=yes
 fromdomain=sip.ritstele.com
 host=sip.ritstele.com
 fromuser=31201234567
 port=38383
 disallow=all
 allow=g729
 dtmfmode=rfc2833

The above will let you use Asterisk with Pilmo. If you don't have a voip phone to use with Asterisk we'll have to do some magic to be able to use the Voicefinder.

Adding the section below to your sip.conf will allow the Voicefinder to register with Asterisk:

 ;let the voicefinder register with asterisk
 [31201234567]
 type=friend
 secret=yourpilmopassword
 defaultip=192.168.1.3
 host=dynamic
 dtmfmode=rfc2833
 username=31201234567@sip.ritstele.com
 disallow=all
 allow=g729
 nat=yes
 canreinvite=no                                                                                                          

The Voicefinder will try to connect to sip.ritstele.com. There are few ways to solve this. You could configure the Voicefinder to use a custom DNS server where you override the sip.ritstele.com hostname (make sure your Asterisk server can still find the real host).
In my setup I redirected the Voicefinder traffic using iptables:

 # CATCH VOICEFINDER
 /sbin/iptables -t nat -A PREROUTING  -i eth1 -d 212.26.192.155 -j DNAT --to-destination 192.168.1.2
 /sbin/iptables -t nat -A POSTROUTING -o eth1 -d 192.168.1.3    -j SNAT --to-source 212.26.192.155


Finally, the Voicefinder reformats the number you're dialing into international format. Keep this in mind when creating your dialplan. E.g. if you dial 1234567 the Voicefinder will tell Asterisk you're dialing 31201234567 (assuming you're Pilmo account is in areacode 020).