I think you're on the wrong project. See OpenStreetmap.org and OpenLayers.org Geolocation/geocoding has nothing to do with SIP or FreeSWITCH. Tools and Wikis on the sites above will give you all the tools you need to build your own slippery map and place your points of interest via database. You will probably collect your GPS coordinates on a public website and and maintain your userbase and maps on a private server. You will need to do alot of coding, but the geospacial rocket science and cool mapping tricks are done with the code on those websites. Did you know you can get an opensource map of the whole world in 6 GB. OpenSource WOW! I'm not going to answer any more of your questions here. I'm just informing you that you need take this quest to the geniuses I've mentioned above, and not the FreeSWITCH geniuses.