Latest is 1.4.0 downloadable from 1.3.x/stable

iLBC codec support is optional.
If you wish to have linphone support iLBC codec,
then download and compile the provided ilbc-rfc3951.tar.gz,
then compile linphone telling him where the ilbc software is installed with
   --with-ilbc= [default=/usr ] configure option.

Simon Morlat
web http://www.linphone.org/