pdu_u16
ttl = pdu_u16(base);
cap.available = pdu_u16(buf +
cap.enabled = pdu_u16(buf +
pvid = pdu_u16(bytes);
autoneg = pdu_u16(buf);
mautype = pdu_u16(buf);
u16 = pdu_u16(bytes);
ttl = pdu_u16(tlv.tlv_payload);
hdr = pdu_u16(buf);
uint16_t pdu_u16(const uint8_t *);