Example tariff algorithm
public class CngSensitiveLinear implements PacketCountTariff {
private CngSensitiveLinearDisplay display;
public float getPrice(int pkin, int pkout, int cng) {
boolean cngWarning = false;
float price = pkin*inRate + pkout*outRate;
if (cng > cngThreshold) { // congestion threshold exceeded
if (pkin > inLimit || pkout > outLimit) { // traffic limits exceeded
display.update(pkin, pkout, cng, cngWarning);