Cannot access sip command from the server

Please i am new to asterisk, i installed asterisk 1.8 and also installed gcc, ncurses,libxml2 dependables. After installation i realised that the module was not present. On logging on to the server i noticed several commands were not available for example sip, restart, save and some other commands were not available.Please what did i do wrong? i have spent all day cracking my head to no avail i even re-installed asterisk and still the same problem

chan_sip probably didn’t get built. That seems to be a running problem now if you don’t install libssl-dev.

Install that, rerun ./configure, and then check.