# An Availability-Enhanced Service Function Chain Placement Scheme in Network Function Virtualization

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## Abstract

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## 1. Introduction

- We formulate the problem of service function chain placement as an integer linear programing (ILP) optimization problem with the objective of minimizing end-to-end delay of an SFC.
- We propose a heuristic algorithm to improve availability by distributing VNFs on multiple substrate nodes on the basis of a layered graph approach.
- We carry out simulation to evaluate the performance of the availability-enhanced scheme in terms of availability, end-to-end delay, and computation time cost on different topologies.

## 2. Related Work

## 3. Layered Graph System Model and Problem Formulation

#### 3.1. Problem Formulation

#### 3.2. Layered Graph System Model

- Create $t$ copies of substrate network graph $G$. The network topology of each copy is the same as $G$’s topology. We denote ${G}^{0}$ as the original substrate network graph and ${G}^{i}$ as the $i$th copy network graph.
- Connect substrate nodes in neighboring network graphs ${G}^{i-1}$ and ${G}^{i}$ vertically if they can host $i$th VNF of the SFC.
- The original substrate graph ${G}^{0}$, $t$ copies of substrate network graphs ${G}^{1}~{G}^{t}$, and edges between these layered networks compose a new graph, denoted as ${G}^{whole}$.
- Find a shortest path between the ingress node in ${G}^{0}$ and the egress node in ${G}^{whole}$. Each transition node on the shortest path connecting $i-1$ and $i$ layers is the selected substrate node to host the $i$th VNF of the SFC.

#### 3.3. Availability Issues

## 4. Availability-Enhanced SFC Placement Scheme

Algorithm 1 Node selection: | |

Algorithm 2 Layered graph based routing: | |

## 5. Evaluation and Analysis

#### 5.1. Simulation Setup

#### 5.2. Performance of Availability

#### 5.3. Performance of End-To-End Latency of SFC

#### 5.4. Performance of Computation Time

## 6. Conclusions

## Author Contributions

## Funding

## Acknowledgments

## Conflicts of Interest

## References

- Recommendation ITU-R M.2083-0. IMT Vision—Framework and Overall Objectives of the Future Development of IMT for 2020 and Beyond; Int’l Telecommunication Union-Radiocommunication Sector: Geneva, Switzerland, 2015. [Google Scholar]
- Kapassa, E.; Touloupou, M.; Stavrianos, P.; Kyriazis, D. Dynamic 5G slices for IoT applications with diverse requirements. In Proceedings of the 2018 Fifth International Conference on Internet of Things: Systems, Management and Security, Valencia, Spain, 15–18 October 2018; pp. 195–199. [Google Scholar]
- ETSI. Network Functions Virtualization: An Introduction, Benefits, Enablers, Challenges & Call for Action; ETSI: Valbonne, France, 2012. [Google Scholar]
- McKeown, N.; Anderson, T.; Balakrishnan, H.; Parulkar, G.; Peterson, L.; Rexford, J.; Shenker, S.; Turner, J. Openflow: Enabling innovation in campus networks. ACM Sigcomm Comput. Commun. Rev.
**2008**, 38, 69–74. [Google Scholar] [CrossRef] - Halpern, J.; Pignataro, C. Service Function Chaining (SFC) Architecture; RFC 7665; IETF: Wilmington, DE, USA, 2015. [Google Scholar]
- Bujari, A.; Palazzi, C.E.; Polonio, D.; Zanella, M. Service function chaining: A lightweight container-based management and orchestration plane. In Proceedings of the 2019 16th IEEE Annual Consumer Communications & Networking Conference (CCNC), Las Vegas, NV, USA, 11–14 January 2019; pp. 1–4. [Google Scholar]
- Quinn, P.; Nadeau, T. Problem Statement for Service Function Chaining; RFC 7498; IETF: Wilmington, DE, USA, 2015. [Google Scholar]
- Mehraghdam, S.; Keller, M.; Karl, H. Specifying and placing chains of virtual network functions. In Proceedings of the 2014 IEEE 3rd International Conference on Cloud Networking (CloudNet), Luxembourg, 8–10 October 2014; pp. 7–13. [Google Scholar]
- Sekar, V.; Ratnasamy, S.; Reiter, M.K.; Egi, N.; Shi, G. The middlebox manifesto: Enabling innovation in middlebox deployment. In Proceedings of the 10th ACM Workshop on Hot Topics in Networks (HotNets-X), Cambridge, MA, USA, 14–15 November 2011; pp. 1–6. [Google Scholar]
- Chen, H.; Abbas, R.; Cheng, P.; Shirvanimoghaddam, M.; Hardjawana, W.; Bao, W.; Li, Y.; Vucetic, B. Ultra-reliable low latency cellular networks: Use cases, challenges and approaches. IEEE Commun. Mag.
**2018**, 56, 119–125. [Google Scholar] [CrossRef] - Han, B.; Gopalakrishnan, B.; Ji, L.; Lee, S. Network function virtualization: Challenges and opportunities for innovations. IEEE Commun. Mag.
**2015**, 53, 90–97. [Google Scholar] [CrossRef] - Chua, F.C.; Ward, J.; Zhang, Y.; Sharma, P.; Huberman, B.A. Stringer: Balancing latency and resource usage in service function chain provisioning. IEEE Internet Comput.
**2016**, 20, 22–31. [Google Scholar] [CrossRef] - Lee, J.; Turner, Y.; Lee, M.; Popa, L.; Banerjee, S.; Kang, J.; Sharma, P. Application-driven bandwidth guarantees in datacenters. ACM Sigcomm Comput. Commun. Rev.
**2014**, 44, 467–478. [Google Scholar] [CrossRef] - Yu, M.; Yi, Y.; Rexford, J.; Chiang, M. Rethinking virtual network embedding: Substrate support for path splitting and migration. ACM Sigcomm Comput. Commun. Rev.
**2008**, 38, 17–29. [Google Scholar] [CrossRef] - Cheng, X.; Su, S.; Zhang, Z.; Wang, H.; Yang, F.; Luo, Y.; Wang, J. Virtual network embedding through topology-aware node ranking. ACM Sigcomm Comput. Commun. Rev.
**2011**, 41, 38–47. [Google Scholar] [CrossRef] - Chowdhury, N.M.M.K.; Rahman, M.R.; Boutaba, R. ViNEYard: Virtual network embedding algorithms with coordinated node and link mapping. IEEE Trans. Netw.
**2012**, 20, 206–219. [Google Scholar] [CrossRef] - Gong, L.; Wen, Y.; Zhu, Z.; Lee, T. Toward profit-seeking virtual network embedding algorithm via global resource capacity. In Proceedings of the 2014 IEEE Conference on Computer Communications (INFOCOM), Toronto, ON, Canada, 27 April–2 May 2014; pp. 1–9. [Google Scholar]
- Dwaraki, A.; Wolf, T. Adaptive service-chain routing for virtual network functions in software-defined networks. In Proceedings of the 2016 Workshop on Hot Topics in Middleboxes and Network Function Virtualization (HotMIddlebox), Florianopolis, Brazil, 22–26 August 2016; pp. 32–37. [Google Scholar]
- Choi, S.; Turner, J.; Wolf, T. Configuring sessions in programmable networks. ACM Comput. Netw.
**2003**, 41, 269–284. [Google Scholar] [CrossRef] - Huin, N.; Jaumard, B.; Giroire, F. Optimization of network service chain provisioning. In Proceedings of the 2017 IEEE International Conference on Communications Workshops (ICC), Paris, France, 21–25 May 2017; pp. 1–7. [Google Scholar]
- Tomassilli, A.; Giroire, F.; Huin, H.; Perennes, S. Provably efficient algorithms for placement of service function chains with ordering constraints. In Proceedings of the 2018 IEEE Conference on Computer Communications (INFOCOM), Honolulu, HI, USA, 16–19 April 2018; pp. 774–782. [Google Scholar]
- Moualla, G.; Turletti, T.; Saucez, D. An availability-aware SFC placement algorithm for fat-tree data centers. In Proceedings of the 2018 IEEE 7th International Conference on Cloud Networking (CloudNet), Tokyo, Japan, 22–24 October 2018; pp. 1–4. [Google Scholar]
- Herker, S.; An, X.; Kiess, W.; Beker, S.; Kirstaedter, A. Data-center architecture impacts on virtualized network functions service chain embedding with high availability requirements. In Proceedings of the 2015 IEEE Globecom Workshops (GC Wkshps), San Diego, CA, USA, 6–10 December 2015; pp. 1–7. [Google Scholar]
- Kong, J.; Kim, I.; Wang, X.; Zhang, Q.; Cankaya, H.C.; Xie, W.; Ikeuchi, T.; Jue, J.P. Guaranteed-availability network function virtualization with network protection and VNF replication. In Proceedings of the 2017 IEEE Global Communications Conference (GLOBECOM), Singapore, 4–8 December 2017; pp. 1–6. [Google Scholar]
- Yala, L.; Frangoudis, P.A.; Ksentini, A. Latency and availability driven VNF placement in a MEC-NFV environment. In Proceedings of the 2018 IEEE Global Communications Conference (GLOBECOM), Abu Dhabi, UAE, 9–13 December 2018; pp. 1–7. [Google Scholar]
- Kathiravelu, P.; Van Roy, P.; Veiga, L. Composing network service chains at the edge: A Resilient and adaptive software-defined approach. Trans. Emerg. Telcommun. Technol.
**2018**, 29, e3489. [Google Scholar] [CrossRef] - Hsieh, C.; Chang, J.; Chen, C.; Lu, S. Network-aware service function chaining placement in a data center. In Proceedings of the 2016 18th Asia-Pacific Network Operations and Management Symposium (APNOMS), Kanazawa, Japan, 5–7 October 2016; pp. 1–6. [Google Scholar]
- Cohen, R.; Lewin-Eytan, L.; Naor, J.S.; Raz, D. Near optimal placement of virtual network functions. In Proceedings of the 2015 IEEE Conference on Computer Communications (INFOCOM), Kowloon, Hong Kong, 26 April–1 May 2015; pp. 1346–1354. [Google Scholar]
- Lombardo, A.; Manzalini, A.; Schembra, G.; Faraci, G.; Rametta, C.; Riccobene, V. An open framework to enable NetFATE (Network Functions at the Edge). In Proceedings of the 2015 1st IEEE Conference on Network Softwarization (NetSoft), London, UK, 13–17 April 2015; pp. 1–6. [Google Scholar]
- Erdős, P.; Rényi, A. On random graphs. Publ. Math.
**1959**, 6, 290–297. [Google Scholar] - Gilbert, E.N. Random graphs. Ann. Math. Stat.
**1959**, 30, 1141–1144. [Google Scholar] [CrossRef] - Orlowski, S.; Wessäly, R.; Pióro, M.; Tomaszewski, A. Sndlib 1.0—Survivable network design library. Networks
**2010**, 55, 276–286. [Google Scholar] [CrossRef]

**Figure 2.**Layered graph approach for deployment of two virtual network functions (VNFs) in a service function chain (SFC).

**Figure 6.**Performance of average end-to-end latency of SFC (100 nodes, edge connection probability 0.5).

**Figure 7.**Performance of computation time of proposed algorithm (100 nodes, edge connection probability 0.5).

**Figure 8.**Performance of computation time of proposed algorithm (50 nodes, edge connection probability 0.5).

**Table 1.**Number of times availability requirements were not met (probability of edge connection 1.0).

Number of VNFs | 50 Nodes | 60 Nodes | 70 Nodes | 80 Nodes | 90 Nodes | 100 Nodes |
---|---|---|---|---|---|---|

5 VNFs | 0 | 0 | 0 | 0 | 0 | 0 |

10 VNFs | 0 | 1 | 0 | 0 | 0 | 0 |

15 VNFs | 1 | 1 | 0 | 1 | 1 | 0 |

20 VNFs | 2 | 1 | 0 | 1 | 1 | 1 |

**Table 2.**Number of times availability requirements were not met (probability of edge connection 0.5).

Number of VNFs | 50 Nodes | 60 Nodes | 70 Nodes | 80 Nodes | 90 Nodes | 100 Nodes |
---|---|---|---|---|---|---|

5 VNFs | 0 | 0 | 0 | 0 | 0 | 0 |

10 VNFs | 0 | 0 | 0 | 1 | 0 | 1 |

15 VNFs | 1 | 0 | 1 | 1 | 1 | 0 |

20 VNFs | 2 | 2 | 1 | 1 | 1 | 1 |

**Table 3.**Number of times availability requirements were not met (probability of edge connection 0.1).

Number of VNFs | 50 Nodes | 60 Nodes | 70 Nodes | 80 Nodes | 90 Nodes | 100 Nodes |
---|---|---|---|---|---|---|

5 VNFs | 0 | 0 | 1 | 0 | 0 | 0 |

10 VNFs | 1 | 1 | 0 | 1 | 0 | 1 |

15 VNFs | 1 | 0 | 1 | 0 | 0 | 1 |

20 VNFs | 2 | 2 | 1 | 1 | 1 | 1 |

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**MDPI and ACS Style**

Xu, Y.; Kafle, V.P. An Availability-Enhanced Service Function Chain Placement Scheme in Network Function Virtualization. *J. Sens. Actuator Netw.* **2019**, *8*, 34.
https://doi.org/10.3390/jsan8020034

**AMA Style**

Xu Y, Kafle VP. An Availability-Enhanced Service Function Chain Placement Scheme in Network Function Virtualization. *Journal of Sensor and Actuator Networks*. 2019; 8(2):34.
https://doi.org/10.3390/jsan8020034

**Chicago/Turabian Style**

Xu, Yansen, and Ved P. Kafle. 2019. "An Availability-Enhanced Service Function Chain Placement Scheme in Network Function Virtualization" *Journal of Sensor and Actuator Networks* 8, no. 2: 34.
https://doi.org/10.3390/jsan8020034