# Enforcing Optimal ACL Policies Using K-Partite Graph in Hybrid SDN
## 4 Proposed Solution
### Decision Tree Traversing for Multiple ACL Policies
(**a**) Number of ACL implementations against a number of ACL policies when the number of switches is varying; (**b**) Number of ACL implementations against number of ACL policies when number of policies is varying. ### Successful Packet Delivery

We study how the different schemes of policy implementation affect the performance of the network. In this section, we present different performance comparison with a varying number of policies. We can observe from the results shown in the following sections that when the number of policies is increased, the successful packet delivery ratio decreases. It is because when the number of policies is increased then policies implemented on the switches require more effort and time to filter traffic according to a specific policy. #### 5.5.1 When Policies Are Placed near the Source

The following Figure 23a shows the successful packet delivery ratio when policies are implemented near source nodes. In this scheme of policy implementation, we can get less successful delivery of packets because filters need to process each packet from the source node. So this decreases the overall successful packets delivery. Form the Figure; it is clear that with an increase in the number of policies, the successful packet delivery decrease. #### 5.5.2 When Policies Are Placed near the Destination

Figure 23b indicates that when policies are implemented near destination nodes then successful packet delivery ratio increases as compared to near-source policy implementation. It happens because less processing is required by the switches to filter the traffic. The graph shows that with the increase of number policies successful packet delivery ratio decreases because a large number of policies require more processing and filtration. #### 5.5.3 When Policies Are Placed Optimally

We have proposed optimal policy implementation that increases the successful packets delivery. Figure 23c shows enhanced successful packet delivery as compared to the other two approaches. Figure 23c shows that with the increase in the number of policies successful packet delivery ratio is decreased. The existing mechanism has a meager SPD ratio. Figure 12.3 SPD for near the Destination policy Implementation Scheme. (**a**) End-to-End Delay Computation when number of switch is varying and number of polices is constant; (**b**) End-to-End Delay Computation when the number of policies is varying and number of switches is constant. ## 6 Conclusions

In this paper, we proposed a novel approach to optimize the implementation of ACL policies in a hybrid SDN. We modeled the network policies using a 3-tuple, and by traversing all the policies, a decision tree is built that indicates the possible communication among source and destination nodes. Then, we traversed the decision tree using the 3-tuple network policy and constructed a K-partite graph to search for the possible placement of ACL policies. Edge weights on the K-partite graph represented the sum of the number of rules and number of transmissions for unwanted traffic. By computing the shortest path for K-partite graph, we got the set of points (i.e., interfaces of routers) where both values (i.e., number of ACL rules and number of transmissions for unwanted traffic) are minimum. This set of points is considered for ACL policy implementation. Simulation results show that our proposed technique outperforms the existing technique in terms of computation time, traffic optimization, SPD, delay, etc. In the future, we would like to use more sophisticated network policies implementation in hybrid SDN. Conceptualization, N.S. and R.A.; methodology, R.A.; software, R.A., W.M. ; validation, R.A. and N.S. ; formal analysis, N.S. ; writing--original draft preparation, R.A.; writing--review and editing, W.M., N.S. ; visualization, R.A.; supervision, N.S. ; project administration, N.S. ; funding acquisition, W.M., R.A. This research received no external funding. The authors declare no conflict of interest. ## References

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