Sample results for the PIONIER network

Here we present sample results of analysis and simulation for the operational Polish academic network PIONIER.

The input data

The network topology is shown in Figure 1 and the traffic matrix with 71 demands is given in Table 1. The data on the network and the load were downloaded from the operator's website at 11pm, February 7, 2007, which offered the data only for the external nodes GEANT2 and TPNet. Since the network load was very light, we multiplied it by ten.

Figure 1. The topology of the PIONIER network.

The bit rates of demands in Table 1 are translated to the mean number of packets per time slot for the analysis. We assumed that an optical packet carries the payload of 10k bits, and that one second has one million time slots. For example, the demand (Szczecin, TPNet) of 1.114Gbps translates to 111.4k of packets per second, and the mean rate of 0.1114 packets per time slot.

Table 1. The traffic matrix for the network.

We assumed the maximum number of allowed hops η = 20 and the maximum δ = 1500, because the network diameter (i.e. the longest path of all shortest paths) has 10 hops and measures 1100km. This means that packets can make up to 20 hops and travel up to 1500km.

The output data

Table 2 reports the fiber utilization obtained with both analysis and simulation. Most of the fibers are lightly loaded, but some are considerably loaded, like fiber (Warszawa, TPNet) reaching 70% of utilization. The average fiber utilization approximated by the analysis is 6.38%, while the simulation says it is 7.58%, so for this example the analysis results differ from the simulation results by 15.8%.

Table 2. The fiber utilization for the network in Figure 1 and the traffic matrix given by Table 1.

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