See reply inline below, Thank you. On Mon, Aug 4, 2014 at 12:08 PM, aawaise <owaisulhaq(a)hotmail.com> wrote: [Muhammad]: better use latest version of kamailio, i.e. 1.4.x instead of older versions. If you insist on using older version them you can use mpath or loadpath kamailio.cfg to select which module you want to use, i.e SER module or Kamailio module. If both are specified in mpath or loadpath then first one will be used. http://kamailio.org/dokuwiki/doku.php/core-cookbook:3.1.x#loadpath 2. I was advised to us macros from dprint.h to see LM_DBG and LM_ERR [Muhammad]: the syntax of LM_ERR and LM_DBG is similar to printf, so if you know how to use standard C method printf, you should understand how these will work. In case you do not understand printf syntax, i strongly recommend NOT to touch kamailio's native code (the .c or .h files). 3. Third, will these logs also print in /var/log/messages in debian linux [Muhammad]: Yes, you can see log messages under log facility defined in kamailio.cfg with "log_facility". http://kamailio.org/dokuwiki/doku.php/core-cookbook:3.1.x#log_facility However, do note that logs printed in syslog will depend on log level defined with "debug" global variable, http://kamailio.org/dokuwiki/doku.php/core-cookbook:3.1.x#debug Therefore, if for example, log level is set to L_INFO then logs of type L_DBG won't print to syslog. 4. What changes should be made in kamailio.cfg to see these logs, i.e log [Muhammad]: set "debug" global config variable to appropriate value as explained above.