Introduction to MPLS Signaling

---

Your commute to work every day is a long one, and it seems to take forever with all the congestion that you encounter. New lanes have recently been added to the highway, but they are reserved as express lanes. Sure, they would cut your travel time in half, but to use them you would have to carry extra passengers. You decide to try it; you decide to carry four additional passengers so that you can use the express lanes.

The four passengers do not cost much more to transport than yourself alone, and they allow you to both increase your speed markedly due to enabling you to use the express lanes and lower the rate of interference from the unpredictable and impossible-to-correct behavior of the routine traffic.

One day, you enter the express lanes and find that they are all mired in bumper-to-bumper congestion (see Figure 3.1). You are angry, of course, because you were guaranteed use of these lanes as express lanes, yet you are confronted with the same routine traffic you faced every day in the regular lanes. As you slowly make your way down the road, you see that construction has closed the routine lanes and diverted the traffic to your express lanes. So, what good is it to operate under this arrangement if regular traffic is simply going to be diverted onto your express lanes?

Figure 3.1: Backed-Up Express Lane

---