## 4 Results and Discussions
#### 4.1.1 Experiment with \(1\) Hardware and \(1\) Software Router  
In the work the comparative experiment of packet processing time with use of a hardware router (Cisco 2801 series) and the developed software router is carried out. The experiment was conducted in 215 laboratories of the Cisco XI training building of the Lviv Polytechnic National University. The routers were configured through the console using the FIFO queue service algorithm, which is set by default. The traffic generator (50,000 packets) was used to monitor the intensity of the incoming traffic created on the interface of the Cisco 2801 series router. The scheme of the experiments is shown in Figure 8.  
In real time mode, graphs were built that showed a packets delay and probability density function of these values by quantity. At the same time, the Wireshark network analyzer detected fragmentation, grouping of packets of the transmitted information flow and confirmation of their delivery. The time delay value for packet fragmentation and packet grouping was detected. The use of Wireshark allowed to monitor the process of data transmission through the router at the network level with the detection of alarm data packets and fixation of network anomalies, which affect the time parameters of quality of service of real-time traffic. Such packets delays are single and range from 10 to 50 ms. Measurement results of packet delay via the Cisco 2801 router are shown in Figure 9.  
Having determined the average packets delay by the hardware router, the server machine performance is selected for the software router, which provides similar delays. Correspondingly, for comparison we chose the Intel Core i5-2410M (2.3 GHz)/RAM 6 GB server. The compared total nodal delay by the software router installed on the servers of different performance with the Cisco 2801 is depicted in Figure 10.  
Figure 8: Experimental scheme for determining the packets delay by a Cisco 2801 hardware router.  
A similar experiment was conducted with the developed software router (Figure 11). Measured result of packet delay via the software--based router is shown in Figure 12.  
Figure 11: Experimental scheme for determining the packets delay by the software—based router.  
Figure 10: Comparison of the total nodal delay by the software router installed on the servers of different performance with the Cisco 2801 server.  
Figure 9: Packets delay caused by the Cisco 2801 router.  
Comparison of the average packets delays caused by the software router and the Cisco 2801 hardware router is shown in Figure 13. Comparison of the probability density functions of packets delays caused by the hardware and software router is shown in Figure 14.  
The conducted studies confirmed the adequacy of the results obtained in the course of experimental simulation of the software router with Cisco 2801 series hardware. The average packets delay caused  
Figure 14: Comparison probability density functions of packets delay caused by hardware and software router.  
Figure 12: Packets delay caused by software—based router.  
Figure 13: Comparison of the average packets delays caused by the Cisco 2801 hardware router and the software router.  
by the hardware router (experiment A)--\(D_{HR(A)_{1}}\) is 695.91 \(\upmu\)s, and through the software--\(D_{HR(A)_{1}}\) 693.47 \(\upmu\)s when processing the same information flow. As we can see, the measured difference between the software and hardware routers is 2.44 \(\upmu\)s. And also the probability density functions of packets processing time caused by hardware router is same in comparison with the packets processing time probability density functions obtained in work [60].  
Also, for more exact reception of results of a time delay of packages created by the Cisco 2801 router. The experiment when the information flow passed through routers A, A-B and A-B-C is carried out.