Software-Defined Networking: An Introduction

Multiple Network Technologies and Easy Adjustment to Changing Conditions

Question:

Write an essay on the "SDN-Software-defined Network".
 

SDN consists of various elements like firewall, hubs, switches, etc., and these elements provide a single physical network to the users. It is based on the multiple network technologies, and it can easily adjust to the changing conditions. It makes changes frequently, or in other terms, it responds to the changes in a fast mode as per the customer requirements. SDN provides a reliable network so that if changes occur in a part of the network, it will not affect the other part of the network (Wood, Ramakrishnan, Hwang, Liu, & Zhang, 2015). It is handled by the two protocols: one is Open flow, and other is OVSDB. It requires less time for storage and computation process. There are Software-defined data centers for handling the storage tasks. Moreover, it is based on the “Pay by Use” technology. SDN provides multiple network technologies, and it can easily adjust to the changing conditions. It makes changes frequently, or in other terms, it responds to the changes in a fast mode as per the customer requirements. The Software-defined Network is also applied on the Wide Area Network. It is based on the Pay-as-you-grow model. It is based on the technology “As the size of infrastructure increases, the amount of rent keeps on increasing”.

Software-defined networking is the heart of the network. A network consists of various elements like firewall, hubs, switches, etc., and these elements provide a single physical network to the users (Ferro, 2016). All the physical entities are dependent on each other i.e. if there is a failure in any physical entity, then it will affect the other entity as well as it will affect the whole network. SDN is a solution to the above problem. SDN provides a reliable network, so that if changes occur in the part of the network, it will not affect the other part of the network.

The hackers create a hole in the software, and then they enter into the software through the hole and harm the software, and the hackers attacked the software before the vendor gets known about the issue. This whole is a zero-day attack (Rolbin, 2016). The attack has been performed by the hackers and the vendor is not familiar with the situation. One of the reasons behind this problem is that the network in the earlier days are quite complex, and it was difficult to manage them, but in today’s era, there are various network management tools to solve this issue. SDN is one of the sources for handling this issue. As it provides proper monitoring on routers and switches, and also it helps in handling the traffic in a proper manner. It helps in solving the various legacy issues.

Now, a day the customer requirements keep on changing continuously, and those organizations survive in the market which adapts themselves to the changing environment, or working conditions. The organization must have the ability to adapts with the changing approaches, strategies of doing work, changing frameworks; those who can change will not survive in the business world. The cloud networking technique and other networking techniques are not flexible as like SDN. SDN provides multiple network technologies, and it can easily adjust to the changing conditions. It makes changes frequently, or in other terms, it responds to the changes in a fast mode as per the customer requirements.

Reliable Network and Handling of Legacy Issues

There are various working parts of SDN: Controller- It is the brain of the SDN, as it provides the centralized view of the network. It monitors the network on real time basis, and also it handles the traffic on a real-time basis (Horvath, 2016). It is handled by the two protocols: one is Open flow, and other is OVSDB. The Open flow protocol provides the communication protocols to the SDN controller, and SDN controller works depending upon the guidance of Open Flow protocol. South bound API’s- It provides protocols (set of rules, and regulations) to the network, which is used for sending data through the routers as well as it is used for sending data through the switches. North bound API’s- It provides communication with the applications, and it also provides the track or the direction to the traffic. 

The social media websites, cloud computing, mobile devices, etc. - all are based on the traditional network. It requires large time for the storage process as well as it requires large time for the computation process. All the network operations are performed manually (in a case of traditional network). But in a case of SDN, it requires less time for storage and computation process (Nedbal, 2016). There are Software-defined data centers for handling the storage tasks. Moreover, it is based on the "Pay by Use” technology.

Software-defined data center consist of various resources i.e. storage, computing, and networking resources, and all the resources are represented in the software form. It is based on the pay use technology. It is used in the similar way as the users use Gas (gas used for cooking purpose, and metropolitan cities the people as have pay bill by use). The users use the gas, according to their requirements, and they have to pay the bill according to the units of gas used by them. In the same way, SDN sold software by requirements. It also helps in saving cost, money, time, and affords. There is no need to create a physical infrastructure. The organization can hire it on the rent basis via a cloud. It provides the centralized infrastructure of the data center. The users can access different application and files through the shared servers. There is no need to invest large amounts in database creation and their updating. The user can for the services used according to the quantity of data used by them. As the network is used by paying the rent; then it is easy to manage or use the large centers. The data centers and the network are handled by the third party, so SDN is one of the vital resources for providing quick response to the users. This is one the reason also that the SDN provides quick response to the required changes.

Software-defined WAN: The Software-defined Network is also applied on the WAN. The Wide Area Network is one of the useful sources for office, and also for the business established at a geographic distance. The cloud-based WAN is used in this case. The user has to pay the amount by the usage. The amount paid by the cloud user, and the amount and services are given by the cloud providers; all the things are defined in the SLA document. The cloud provider provides facilities to the cloud user depending on the rules, and regulations defined in the SLA document.

SDN's Role in Securing Networks

There are various benefits of SDN: Directly programmable: The programming is done based on the automation tools and theses are open source tools. Centralized management: It provides the centralized network which acts as a source for providing fully monitors service to the network. It is based on the Pay-as-you-grow model. It is based on the technology “As the size of infrastructure increases, the amount of rent keeps on increasing”. Flexibility: It is flexible with the required changes. It meets all the requirements i.e. required for services, and applications (on quick basis). Creative: The organization can create new applications as well as new services by using SDN. 

In the traditional network, the physical entities are dependent on each other and changes or the failure in one of the entity destroys the entity. To eliminating this problem, SDN is currently used. It provides a reliable network so that if changes occur in the part of the network, it will not affect the other part of the network (Ferro, 2016).  But, this has given birth to a big security issue. If the hackers attack the controller, it will affect the whole network. The controller is the centralized part of SDN, and it monitors and handles the traffic of the whole network, so it is a single point of attack for the attackers, and this is the main target for the hackers. If the controller part of the SDN is getting affected, then it will destroy the full network as well as other resources (which are part of the network).

The Open flow protocol is a big source for providing the communication protocols to the SDN controller, and SDN controller works depending upon the guidance of Open Flow protocol. But on the other hand, if threat occurs on open flow protocol then, it will affect the availability, as well as the integrity of the network, and moreover, it degrades the performance of the network.

The denial of survive attacks is one of the issues that occur in this type of network. This attacker does not allow the authorized person to access the system, as their system gets hacked by the attackers. The attackers access the system of the authorized person, and make changes in the information. The second is attack by the thwart scanning technique. The attacker’s uses thwart scanning technique for hacking the IP address. They access the Random virtual IP dress and make changes in the IP address. The change in the IP address of one system will affects the whole system (as the systems are interrelated to each other). The third issue is replication diversity. The replications copies of main controller are created and it takes lot of space of the memory, and affects the system. As the number of applications increases, the replication copies of the controller keep on increasing. This cause an improper behavior in the network. It is a kind of virus in which creates multiple instances of the controller, and it occupies the space of the system, and further it affects the performance of the system. By creating the bundle of copies of controller, the performance of the system get degrades. The replicate copies of the controller is created depending on the application i.e. as the number of running applications increases, the duplicate copies of controller increases. 

Benefits of SDN

The controller is one of the vital sources for handling the various tasks of the network. It maintains and monitors the whole network. In other terms, it is known as the heart of the network. If the controller part of the SDN gets affected, then it will disturb or destroy the whole network. As the attackers know that it is the main source or the component of SDN, so this is the main attack or the target point for the hackers (Dhamecha, & Trivedi, 2013). This is the single point of track for the attackers, as it affects the working of the whole network. This is the current issue which is faced by the organization (which are using this technique of network).

The solution to eliminating this problem is that the security applications should be installed on the controller, so that this part is affected or going to affects by the attackers, then it get traced by the organization. The firewall is one of the solutions for resolving this problem. It is a combination of hardware as well as software, and it helps in securing data from the outsiders. These outsiders are any authorized person which is not a part of organization (McClure, 2011). The firewall should be installed on the controller, so that hackers can access the network of the industry. The solution to this problem is encryption technique. If the hackers try to access the data through controller, then they can’t make changes in the data, and this is possible only if the data is present in the encrypted from (LUO, & XU, 2013). The private key for accessing or unlocking the data is known only to the sender, as well as to the receiver of the data. The other solution to this problem is use of strong password. The two times verification password can be used. It means while creating a password the user has to move through two steps for creating the password. The user enter the password, and moreover, the user has to enter the mobile number, and verification code is sent on the number, and user has to enter that number as a verification key while creating the account. This is an important step so that only the authorized user i.e. the user having an account on the network can access the information. Further, the password can be made more secure by using special characters along with the number or along with the date of birth of the person so that it can't be easily crack by the hackers. The information or the data should be used for the constructive purposes. There should be strict or complex data security methods in the organizations so that no one can harm the data. There should be strict cyber-security methods, and there be, a cyber-security team in every company that can detect hackers and protect the company from hackers. The hackers should be strictly punished so that they will hundreds of times before committing any crime.

Working Parts of SDN

No doubt, the information is managed at the centralized point, but to protect the data, a copy of information should be placed on the private database. The organization should go for the Hybrid SDN model. As this model is a combination of both private and public models. No doubt, it is an expensive and complex method, but it is the best option for securing the sensitive data. The Company can secure the critical data, by placing it in the private database, and they can place the remaining data in the public place i.e. on the centralized database. 

SDN is based on the “Pay by Use” technology. Software-defined data center consist of various resources i.e. storage, computing, and networking resources, and all the resources are represented in the software form. It is flexible with the required changes. It meets all the requirements i.e. required for services, and applications (on quick basis). It is based on the pay by use technology. It provides the centralized network which acts as a source for providing fully monitors service to the network. It is based on the Pay-as-you-grow model. It is based on the technology “As the size of infrastructure increases, the amount of rent keeps on increasing” (Ferro, 2016). The controller is the main component of SDN. It is known as the heart of the network. If the controller part of the SDN gets affected, then it will disturb or destroy the whole network. To eliminating this problem is that the security applications should be installed on the controller, so that this part is affected or going to affects by the attackers, then it get traced by the organization. The firewall and the encryption technique are the best solutions for resolving this problem.  

References

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Dhamecha, K. & Trivedi, B. (2013). SDN Issues A Survey. International Journal Of Computer Applications, 73(18), 30-35.

Ferro, G. (2015). Software-defined networking explained in 10 easy steps. InfoWorld.

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Horvath, R. (2016). A Literature Review on Challenges and Effects of Software-defined Networking .

Li, X., Qian, H., Yu, Y., Weng, J., & Wang, Z. (2013). Robust password changing and DoS resilience for human-centric password authentication. Security And Communication Networks, n/a-n/a.

LUO, W. & XU, M. (2013). Attribute-based encryption and re-encryption key management in cloud computing. Journal Of Computer Applications, 33(10), 2832-2834.

McClure, B. (2011). The firewall behind the firewall. Computers & Security, 17(4), 325.

Nedbal, D. (2016). A Literature Review on Challenges and effects of Software-defined Network.

Reza Amini, M., Balarastaghi, E., & Branch, B. (2011). Universal Neural Network Demodulator for Software-defined Radio. IJET, 3(3), 263-268.

Rolbin, M. (2016). Early detection of network threats using Software-defined Network (SDN) and virtualization.

Wood, T., Ramakrishnan, K., Hwang, J., Liu, G., & Zhang, W. (2015). Toward a software-based network: integrating Software-defined networking and network function virtualization. IEEE Network, 29(3), 36-41.