The emergence of Cloud Computing is a paradigm shift in provisional networking resources on demand that offer their services on a pay-as-you-go basis. SDN-based cloud is the newest type of cloud technology in which SDN is used to acquire control of network configuration to provide Networking-as-a-service (Naas) in cloud computing environments.

It has acquired scalable and elastic computing along with a subscription-oriented service model. SDN-based Cloud Computing focuses on data center power optimization, traffic engineering, network virtualization and security. SDN features bring huge benefits to Cloud Computing, such as,

 •  Adapting to dynamically changing workloads
 •  Network security enhancement
 •  Programmable control plane
 •  Network virtualization
 •  Global view of DCN
 •  Energy Conservation
 •  Integration of hypervisor

Recently, more different techniques and algorithms have been implemented in cloud computing based on SDN,

 •  Resource Management
 •  Resource scheduling
 •  Resource allocation
 •  Energy conservation
 •  Load balancing
 •  Quality of Services

Virtualization technology has also been included in SDN-based Cloud Computing to facilitate flexibility and scalability in virtual computing nodes, storage and network resources to provide the resources as services to cloud users.

Moreover, Software-defined networks for Resource Allocation (RA) in cloud computing aim to optimize applications, i.e., Improved resource utilization, power efficiency and type of Information and Communication Technologies (ICT) resources allocated to end-users.

Therefore, integrating a cloud computing environment can solve most of the previous problems in resource allocation. Recently, RA gained a large amount of relevance in addressing the issue of power consumption in Cloud computing. Dynamic RA has been classified according to their strategies in use-based RA, market-based dynamic RA and dynamic SLA-based RA. Also, RA problems can be classified based on numerous dimensionality as follows :

 •  Resource adaption policy
 •  Objective function
 •  Allocation method
 •  Assignment process
 •  Interoperability

SDN-based cloud computing has many advantages compared with traditional cloud in terms of,

 •  Security
 •  Quality of Services
 •  VM Orchestration
 •  Reducing capital expenditure (CapEx)
 •  Operational expenditure (OpEx)

Although SDN-based cloud computing reveals many good features and faces several challenges that must be taken into consideration that includes,

 •  Performance
 •  Availability
 •  Scalability
 •  Security