SC_LOOP_TRAFFIC
#define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \
if (ppp->flags & SC_LOOP_TRAFFIC) {
(ppp->flags & SC_LOOP_TRAFFIC) == 0) {
(ppp->flags & SC_LOOP_TRAFFIC) == 0)