Hello Yamamoto-san,
Timesys provides the ppp package, which contains the PPP (Point-to-Point Protocol) daemon. If you are using the Web Factory, you can add this package to your web build during the package selection step. If you are using the Desktop Factory, you can run the following command from your top-level Factory directory to include ppp in your build:
make ppp-select && make
Thanks, and let me know if you have any questions.
Timesys Support