mjSIP (standard edition) natively works on both JSE (starting
from Java 1.3) and JME/CDC (actually JME/CDC/PersonalProfile1.0).
However it is also available a porting of mjSIP to JME/CLDC;
it is called mjSIP2ME (mjSIP-to-J2ME) and runs on J2ME/CLDC1.1/MIDP2.0.
mjSIP2ME differs with the standard mjSIP just on the implementation
of very few classes, and offers the same APIs to the upper
layers.
The porting from mjsip to mjsipME is very simple and can
be also easily done starting from a fresh mjsip distribution
following few documented steps.