id(int,auto) ruid(string) username(string) domain(string,null) contact(string) received(string,null) path(string,null) expires(int) q(double) callid(string) cseq(int) last_modified(int) flags(int) cflags(int) user_agent(string) socket(string,null) methods(int,null) instance(string,null) reg_id(int) 
