# A Design for SDN-Based Identifier-Locator Separation Architecture on IoT Networks
## 3 Proposed SDN-Based Identifier-Locator Separation Architecture for IoT Networks
### Main Procedure
#### 3.4.2 Route Optimization Process
Because MOFI performs packet encapsulation to transmit packets, it requires an additional header. In contrast, the proposed scheme only performs field replacement and forwards packets to the destination. Thus, it is believed that packet encapsulation leads to performance degradation in the case of packet transmission. If the nodes in the network are constrained and the number of nodes is huge, such as in the IoT environment, packet encapsulation can cause delays in data transmission and the amount of data that can be delivered within one segment is smaller. The total cost was calculated with signaling cost and packet forwarding cost. The cost comparison is based on the cost model depicted in Figure 4. Figure 6a illustrates that MOFI showed a better performance than the proposed scheme under the session length of 3.84 Kbytes. However, the performance was changed to be better over the session length of 3.84 Kbytes. The signaling cost was not influenced by the session length, but the session length was the major factor in the increase of the packet delivery cost. As the session length increased, the extra overhead for encapsulation was increased. As we mentioned earlier, the costs for signaling and packet forwarding were calculated based on the cost model that we suggested. Therefore, the results, except for those in Figure 6b, were calculated under equivalent conditions. In addition, we considered the case that the number of hops between the ARs were different, but the number of data packets were fixed. Figure 6b illustrates the comparison of the total cost between MOFI and the proposed scheme according to the variation of number of hops between the ARs with 100 packets. The proposed scheme showed a better performance than MOFI when the packets traversed more ARs. ## 6 Conclusions

In this paper, we proposed an SDN-based ID-LOC separation architecture for IoT networks. We concentrated on how to design and to provide scalability without any modification of the end nodes in the IoT network, and we tried to overcome the shortcomings that were caused by the binding of the IP addressing system. As a result, the paper showed the architecture and described the processes of registration, packet forwarding, and route optimization. The proposed scheme separates the

Figure 6: Total cost comparison between MOFI and the. proposed scheme: (**a**) fixed number of hops between ARs (5); (**b**) fixed number of data packets (100). underlying network into an EID domain and an IP domain to route the unrouteable EIDs. The hosts do not participate in the signaling procedure, and they do not consider any conversion procedure between the IDs and the LOCs. To analyze the signaling and packet forwarding costs, we configured a network topology and suggested a cost model for signaling and packet forwarding. Additionally, we calculated the signaling and packet forwarding costs with several parameters, and we compared our scheme with one of the existing solutions. From the analytical result, MOFI has a lower signaling cost than the proposed scheme, but it consumes more cost in packet delivery because it generates additional overhead through the use of tunneling. The total cost is influenced by the number of hops between the OFSs and session length. It was shown that the signaling overhead is negligible when the exponential increase of session size is considered. The analysis model proposed in this paper is the result of analysis that considers only normal and general cases. In a real environment, there are various variables such as network errors and device failures, so many situations need to be considered. In the future, simulation analysis will be conducted on the proposed architecture through simulation tests to verify the analysis model. By constructing and applying a test environment modeling a real environment, it will be possible to improve the performance of the proposed technology and the analytical model. Formal analysis, C.H.L. and J.S.P. ; funding acquisition, J.S.P. ; methodology, C.H.L. and J.S.P. ; project administration, J.S.P.