MPPE_CCOUNT_SPACE
state->ccount = MPPE_CCOUNT_SPACE - 1;
state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE;
if ((ccount - state->ccount) % MPPE_CCOUNT_SPACE
> MPPE_CCOUNT_SPACE / 2) {
state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE;
state->ccount = (state->ccount + 1) % MPPE_CCOUNT_SPACE;
256) % MPPE_CCOUNT_SPACE;