- # Create a base packet and pad it to size
- payload_len = max(0, self.framesize - len(base_pkt_a) - 4) # No FCS
+ # Create a base packet and pad it to size; deduct FCS
+ payload_len_a = max(0, self.framesize - len(base_pkt_a) - 4)
+ payload_len_b = max(0, self.framesize - len(base_pkt_b) - 4)