## 5 Evaluation of Mobility Multihoming Duality
### Mobility-Multihoming Duality Performance Measurements  
By combining the two sets of actions listed above, ILNP hosts can dynamically add and remove a network without disruption to the communication flow. This allows the host to move completely away from the initial network and then back (if required). This in turn realises completely agile and flexible network connectivity between the two hosts--_mobility-multihoming duality_. Figure 7 gives a timeline breakdown of this mobility-multihoming duality scenario.  
Figure 7: A timeline diagram showing an example of a mobility–multihoming duality scenario. The MN has three interfaces, and the CN has one interface. The MN starts communication only on network aa. The MN and the CN begin a communication session using a single interface on both sides. The MN activates interface 2, receives L64 (IPv6 prefix) bb, sends an LU, and sets the new L64 as ACTIVE. The CN responds with an LU-Ack, acknowledging the new set of L64 values that the MN now has. The MN continues to activate another interface, which is also signalled to the CN. The MN then lists the first interface in the net.ilnp6.disabled_interface_syctl list, triggering another LU and state changes in the ILCC. After the CN acknowledges the removal of the first interface, the MN removes the interface.  
The following describes the procedure of the mobility-multihomed scenario that was executed, and it is also summarised in Figure 8:  
Figure 8: The procedure for a data collection run. Both CN and MN initially have only a single interface (i/f) enabled. iperf2 is started with bi-directional data transfer. Additional interfaces are enabled at the MN until all interfaces are enabled. Then, interfaces are disabled at the MN until only a single interface remains enabled. This is repeated so that all additional interfaces have been enabled/disabled twice.  
1. Enable one interface on both the CN and the MN Specifically, the MN will enable interface 1 initially.
2. Begin bi-directional data transfer between two hosts using iperf2. Note that the iperf2 binary was not modified: it was the standard binary operating as if it was using the IPv6.
3. Trigger the MN's movement scenario, which enables additional interfaces. 1. Enable another interface. 2. Wait for handover duration.
4. Repeat step 3 until all interfaces are up and enabled. At this point, the MN has three interfaces enabled for the first time.
5. Trigger the MN's movement scenario disabling interfaces. 1. Disable another interface. 2. Wait for handover duration.
6. Repeat step 5 until all but one interface is up.
7. Repeat steps 3-5 once such that there are two occasions where all interfaces are up, and then to return to the single-interface state.
8. Terminate the data transfer.  
In this experiment, TCP and UDP flows generated using iperf2 were used. In addition, three artificial delays were induced in the configuration to emulate different Internet scenarios, as described in Table 7. The National and Intercontinental RTT values were chosen based on measurements conducted by the authors from their home networks in the UK. The order of magnitude difference between delay values also presents a good scope for a performance comparison.