apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 049AD65B
echo "deb http://apt.opensips.org trusty 2.4-releases" >/etc/apt/sources.list.d/opensips.list
apt-get install build-essential openssl bison flex
get perl and mysql
apt install perl libdbi-perl libdbd-mysql-perl libdbd-pg-perl libfrontier-rpc-perl libterm-readline-gnu-perl libberkeleydb-perl ncurses-dev mysql-server libmysqlclient-dev
goto https://opensips.org/pub/opensips/latest/ and download latest package
cd /usr/src
wget https://opensips.org/pub/opensips/latest/opensips-2.4.5.tar.gz
tar -zxvf opensips-2.4.5.tar.gz
build
cd opensips
make all
make install