http://www.asteriskpbx.com/support/features
http://www.trixbox.org/wiki/trixbox-features (copypaste z asterisku)
http://www.openser.org/dokuwiki/doku.php/capabilities:index
http://www.iptel.org/ser/features
Porovnania:
http://en.wikipedia.org/wiki/Comparison_of_VoIP_software#Server_software (len stručné)
http://siprouter.onsip.org/doc/gettingstarted/ch03s04.html – SER vs OpenSER (bez vlastností)
http://snapvoip.blogspot.com/2007/05/openser-vs-ser-running-on-3000-lintel.html