address_field addr = head->addr;
uint8_t ctr = head->control;
uint16_t ilen = head->length.bits.len;
uint8_t ctr_type,pf,dlci,fcs;
uint8_t pf,dlci,fcs;
dlci = GET_DLCI(addr);
pf = GET_PF(ctr);
ctr_type = CLR_PF(ctr);
/* ctr_type = CLR_PF(ctr); */
fcs = *(ptr + len - 1);
printf("cr %d dlci %d pf %d ilen %d fcs 0x%x ", addr.cr, dlci, pf, ilen, fcs);