Thanks, I think, I detected the Problem myself now. It's about using the kamailio S-CSCF as presence server and it's about the config files - examples/scscf/scscf.cfg - examples/scscf/kamailio.cfg When I comment out the DB_URL/DB_URL2 Parameter in scscf.cfg, as follows # Connection URL for the database: ##!define DB_URL "con1=>mysql://scscf:heslo@192.168.5.1/scscf" ##!define DB_URL2 "con2=>mysql://scscf:heslo@10.1.27.217/scscf" then I think, the following command in kamailio.cfg leads to a segmentation fault after kamctl start (this is an assumption) # -- presence params -- modparam("presence", "subs_remove_match", 1) #means we match subscriptions on all attributes because the presence module has not been loaded, because DB_URL is NULL. As a Workaround, I load the presence module always, not only when DB_URL is not NULL. ##!ifdef DB_URL loadmodule "presence" ##!endif Any similar experiences? All the best