Dear List:<br><br>Please correct me if I am wrong, but as I understand the requirement to connect an IP-PBX to the PSTN via a SIP trunking service provider (ITSP), a SIP proxy service and a SIP registration service are required local to the IP-PBX. Does Asterisk include this functionality and/or are there other open source projects providing these SIP services?<br>
<br>Thanks a bunch!<br><br>John<br>