Hello, On 07/03/16 23:23, anthony gonzalez wrote: handling properely transfer to full range of devices out there, could require processing DTMF codes (specially old gateways to pstn) and also a transfer may result in transconding, so a full media engine may be the safest bet. Most of the customers I work with prefer to use what they are more familiar with (hardware is cheap, you can use kamailio load balancing for scalability in front of a farm), those being mostly Asterisk of FreeSwitch -- both should have quite good documentation out there and large communities. Some are using Sems, but you may need to invest more of your time to learn/tune it by eventually digging in sources, if you start from scratch, given it has not much documentation and community there, on the other hand, probably is the smallest in footprint. Asterisk, FreeSwitch and Sems are media servers as well. There is also sippy b2bua which is open source, but signaling only, written in python, iirc, I met it in some deployments over the time, although not that often. Cheers, Daniel -- Daniel-Constantin Mierla http://www.asipto.com http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda Kamailio World Conference, Berlin, May 18-20, 2016 - http://www.kamailioworld.com