# SRv6-Based Edge Service Continuity in 5G Mobile Networks +
## 6 Testbed and Performance Evaluation
### Performance Evaluation
#### 6.2.3 Analysis in Dynamic Conditions  
We evaluated our approach in time intervals within which the container is migrated. We considered four different scenarios. The first, _No Migration SR_, is the baseline, where the container is not migrated. The second, _No Buffer SR_, migrates the container without any packet buffer. The third, _Target Buffer SR_, uses a packet buffer instantiated on the UPF within the target MEC Host. The last, _Ingress Edge Buffer SR_, involves a packet buffer executed on the UPF placed within an MEC Host connected to the ingress edge node. In all the scenarios, SRv6 is used to steer the packets. Figure 19 shows the throughput of an iperf3 application, measured at the server side, over a 10 s time interval including migration. The client sent 5 MB to the server with a bandwidth limited to 1.5 Mbps. The throughput is measured for each of the network topologies described previously. The considered server container required, on average, 3.19 s for migration. Figure 19 confirms the throughput stability of around 1.5 Mbps in static conditions and shows similar performances in the other three scenarios. They have a similar throughput drop during the container downtime, despite the considered topology. The main difference is the time required by the throughput to go back to its original stable value. The _No Buffer_ scenario takes more compared to the buffering cases, and the difference increases with the network depth. The explanation for this outcome is based on the necessity to retransmit lost packets, requiring them to traverse the entire  
Figure 18: Mean request-response time. network before reaching their target destination. To conclude, Figure 19 shows the slight superiority of the _Target Buffer_ compared to the _Ingress Edge Buffer_ despite the topologies. Figure 20 shows the boxplot of the throughput in the four scenarios listed above, using the same network topologies. Data are taken from a 10 s time interval containing migration, and they have been aggregated. The boxplot graphs appear as expected, following the conclusions taken from those of Figure 19. In the _No Migration_ scenario, the box is collapsed in a line, corresponding to the median. This is due to the throughput constant value of around 1.5 Mbps. The _No Buffer_ case, instead, has the wider box, due to a larger number of values equal to zero and to the slower throughput increment after container restoration. The reason is the packet retransmission. The buffering cases have a better performance compared to the _No Buffer_ one. Their throughput increases faster, with the _Target Buffer_ exceeding the _Ingress Edge Buffer_. Finally, as shown in Figure 21, we analyzed the performance in terms of the request-response time in a dynamic scenario, using the TCP-based client-server application already exploited in Section 6.2.2. In this case, the container migration procedure lasts 3.28 s, on average. As shown, the _No Migration_ scenario is the best, as expected. Concerning the migration cases, those approaches with buffer outperform the one without it, and they have a similar performance irrespective of the topology. The use of the buffer, enabling the prevention of packet losses, allows having the increase in the request-response time as close as possible to the container downtime, in the worst case. Figure 19: Throughput within a time interval containing migration. Figure 21: eCDF of the request–response time. Figure 20: Boxplot of the throughput within a time interval containing migration. The conducted experiments demonstrate that our proposed solution guarantees service continuity in the presence of edge service migration, as per the definition provided in Section 1. Specifically, we verified that our approach allows a client to transparently reach its edge service after migration by using the very same IP address and while leveraging the original TCP connection. Moreover, the graphs show how our solution allows the throughput to be the same before and after service migration.