Hello Ajay,
The ppp_stop command will stop pppd and leave it that way. Same for ppp_start, starts pppd. These two commands run “/etc/init.d/ppp stop|start”.
The ppp toggle is kind of weird in that I do not know exactly what it’s use is, but all it does is check if pppd is running, and if it is it will stop it. If pppd is not running, it will start it. From an external viewpoint if I were using the API I don’t know when I would use it because as with any normal programming I would always want things to be as deterministic as possible (am I starting it or stopping it?). Just my two cents.
Jeff