This is just routing "PSTN" calls to/from the correct PBX, and you're looking for a box to distribute calls to the correct location (along with some 'on net' routing to avoid sending calls that should be from one pbx to another to the actual PSTN)? There are some modules like dbalias, dialplan, carrierroute, dispatcher, etc. that can be used for this, but you can use sqlops to write arbitrary queries to your DB for call routing. First assess the source of the initialI NVITE - is this from a PSTN or one of your PBXs? This is the first of the three A's (Authentication, Authorization, and Accounting). You can do this by IP address (the permissions module is helpful here, or again, roll your own), If it's from one of your PBXs, you'll know who to account the call to. It's also possible to issue an authentication challenge (auth and auth_db modules) rather than authenticating by IP address. Usually you'd peer with PSTN carriers by IP address. Next, determine the destination and if the calling party has permissions to reach it. For inbound calls from the PSTN, this is looking up the RURI user in a table (try the alias_db module) to determine if the number belongs to one of your PBXs, and if so which one. If it's from the PSTN and isn't a known number reject it (404 not found), and if it is for a PBX, relay it to the PBX. If the initial invite is from one of your PBXs, still check to see if it's in your DB (an on-net number) and if so, route it. If it's destined for the PSTN, then check any rules on whether or not the call is allowed (i.e. international calling might not be allowed to every country), and route it. That's the general jumping of point. You might have other needs (failover routing, caller id dips, etc), but that should get you started. Regards, Kaufman From: Wayne Wenthin via sr-users &lt;sr-users(a)lists.kamailio.org&gt; Sent: Tuesday, April 9, 2024 3:06 PM To: sr-users(a)lists.kamailio.org Cc: Wayne Wenthin &lt;wayne.wenthin(a)cascadetech.org&gt; Subject: [SR-Users] Newbie looking for advice CAUTION: This email originated from outside the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe. Hi All, I'm new to Kamailio but have been running dozens of Freepbx systems for the last 10 years. We are an Education Service District and service K-12 schools. Many of these we provide dial tone to, the rest we have connections to to provide for toll avoidance and backup outbound calling when the LEC fails. Our main focus is to save schools money that can be used for education instead of infrastructure. Right now I have a single freepbx machine that is using inbound routes to send calls to the proper school district. I would like to replace this with a Kamailio server instead but can't seem to get my mind around the best way to do this. I have 119 inbound routes in my current system with 22 trunks to the other districts. This may increase in the future as we try to migrate districts off of the expensive systems to a more open source way of calling. Currently calls between districts take the route out of the system just to come right back in to be routed to a different district. I would like to avoid that if possible. I've been trying to educate myself on the best practice in this type of structure but can't seem to figure out the best way to make this work. Most of the videos and websites assume a pretty intimate knowledge of Kamailio. That and the database structure doesn't make sense to me. I would like to keep each freepbx as its own registrar as we have lots of crossover with extensions and a few of the districts have their own staff that manage that aspect of the machines. . Any suggestions would be appreciated. Please ask questions if this just looks like I'm rambling. -- Wayne Wenthin Wide Area Network Administrator | CTA@MESD 503.257.1562 Phone/Fax www.cascadetech.org<http://www.cascadetech.org/>