I tried it out and it worked, I used voip stunt, which is the same is voip buster, the same company has many different names.
If you have a voipbuster account just replace
all the information is here:
http://www.voipbuster.com/en/sipp.html
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# This is a comment in the config file.
# Set the URL of local ID (used in From header) (e.g.: sip:
[email protected])
--id sip:sip.VoipStunt.com
# Set the URL of registrar server (e.g.: sip:example.com)
--registrar sip:sip.VoipStunt.com
--domain sip.VoipStunt.com
# Set realm (note: wildcard is now accepted) (e.g.: example.com)
--realm sip.VoipStunt.com
# Set authentication username
--username user
# Set authentication password
--password pw
# Mandatory (for the moment) override the Contact information
# (e.g.: )
--contact
# Optional registration interval (default 55) (for freephonie set 1800)
--reg-timeout 1800
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When you want to make an outgoing call dial 001
eg 0013215551234
area code 321 number 555 1234
and --contact is my computer information
G being my user name and 192.168.1.100 being my computer's LAN IP address 5060 is the port number for voipstunt/voipbuster it's listed in on the page linked above.