Software Defined Networking (SDN) ?????

What is SDN?

The physical separation of the network control plane from the forwarding plane, and where a control plane controls several devices.

Software-Defined Networking (SDN) is an emerging architecture that is dynamic, manageable, cost-effective, and adaptable, making it ideal for the high-bandwidth, dynamic nature of today's applications. This architecture decouples the network control and forwarding functions enabling the network control to become directly programmable and the underlying infrastructure to be abstracted for applications and network services. The OpenFlow® protocol is a foundational element for building SDN solutions. The SDN architecture is:

• Directly programmable: Network control is directly programmable because it is decoupled from forwarding functions.
• Agile: Abstracting control from forwarding lets administrators dynamically adjust network-wide traffic flow to meet changing needs.
• Centrally managed: Network intelligence is (logically) centralized in software-based SDN controllers that maintain a global view of the network, which appears to applications and policy engines as a single, logical switch.
• Programmatically configured: SDN lets network managers configure, manage, secure, and optimize network resources very quickly via dynamic, automated SDN programs, which they can write themselves because the programs do not depend on proprietary software.
• Open standards-based and vendor-neutral: When implemented through open standards, SDN simplifies network design and operation because instructions are provided by SDN controllers instead of multiple, vendor-specific devices and protocols.

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Computing Trends are Driving Network Change

SDN addresses the fact that the static architecture of conventional networks is ill-suited to the dynamic computing and storage needs of today’s data centers, campuses, and carrier environments. The key computing trends driving the need for a new network paradigm include:

• Changing traffic patterns: Applications that commonly access geographically distributed databases and servers through public and private clouds require extremely flexible traffic management and access to bandwidth on demand.
• The “consumerization of IT”: The Bring Your Own Device (BYOD) trend requires networks that are both flexible and secure.
• The rise of cloud services: Users expect on-demand access to applications, infrastructure, and other IT resources.
• “Big data” means more bandwidth: Handling today’s mega datasets requires massive parallel processing that is fueling a constant demand for additional capacity and any-to-any connectivity.

In trying to meet the networking requirements posed by evolving computing trends, network designers find themselves constrained by the limitations of current networks:

• Complexity that leads to stasis: Adding or moving devices and implementing network-wide policies are complex, time-consuming, and primarily manual endeavors that risk service disruption, discouraging network changes.
• Inability to scale: The time-honored approach of link oversubscription to provision scalability is not effective with the dynamic traffic patterns in virtualized networks—a problem that is even more pronounced in service provider networks with large-scale parallel processing algorithms and associated datasets across an entire computing pool.
• Vendor dependence: Lengthy vendor equipment product cycles and a lack of standard, open interfaces limit the ability of network operators to tailor the network to their individual environments.

Software-Defined Networking is Not OpenFlow

Often people point to OpenFlow as being synonymous with software-defined networking, but it is only a single element in the overall SDN architecture. OpenFlow is an open standard for a communications protocol that enables the control plane to interact with the forwarding plane. It must be noted that OpenFlow is not the only protocol available or in development for SDN.

The Benefits of Software Defined Networking

Offering a centralized, programmable network that can dynamically provision so as to address the changing needs of businesses, software-define networking also provides the following benefits:

• Directly Programable:  Network directly programmable because the control functions are decoupled from forwarding functions.which enable the network to be programmatically configured by proprietary or open source automation tools, including OpenStack, Puppet, and Chef.
• Centralized Management:  Network intelligence is logically centralized in SDN controller software that maintains a global view of the network, which appears to applications and policy engines as a single, logical switch.
  Reduce CapEx: Software Defined Networking potentially limits the need to purchase purpose-built, ASIC-based networking hardware, and instead supports pay-as-you-grow models
• Reduce OpEX: SDN enables algorithmic control of the network of network elements (such as hardware or software switches / routers that are increasingly programmable, making it easier to design, deploy, manage, and scale networks. The ability to automate provisioning and orchestration optimizes service availability and reliability by reducing overall management time and the chance for human error.
• Deliver Agility and Flexibility: Software Defined Networking helps organizations rapidly deploy new applications, services, and infrastructure to quickly meet changing business goals and objectives.
• Enable Innovation: SDN enables organizations to create new types of applications, services, and business models that can offer new revenue streams and more value from the network.

Why Software Defined Networking Now?

Social media, mobile devices, and cloud computing are pushing traditional networks to their limits. Compute and storage have benefited from incredible innovations in virtualization and automation, but those benefits are constrained by limitations in the network. Administrators may spin up new compute and storage instances in minutes, only to be held up for weeks by rigid and oftentimes manual network operations.
Software-defined networking has the potential to revolutionize legacy data centers by providing a flexible way to control the network so it can function more like the virtualized versions of compute and storage today.

Software Defined Networking Use Cases

As detailed above, Software Defined Networking offers several benefits for businesses trying to move into a virtual environment. There are a multitude of use cases that SDN offers for different organizations, including carrier and service providers, cloud and data centers, as well as enterprise campuses.
For carrier and service providers, Software-Defined Networking offers bandwidth on demand, which gives controls on carrier links to request additional bandwidth when necessary, as well as WAN optimization and bandwidth calendaring. For cloud and data centers, network virtualization for multi-tenants is an important use case as it offers better utilization of resources and faster turnaround times for creating a segregated network. Enterprise campuses experience network access control and network monitoring when using Software-Defined Networking policies.

With SDN, the administrator can change any network switch's rules when necessary -- prioritizing, de-prioritizing or even blocking specific types of packets with a very granular level of control. This is especially helpful in a cloud computing multi-tenant architecture, because it allows the administrator to manage traffic loads in a flexible and more efficient manner. Essentially, this allows the administrator to use less expensive commodity switches and have more control over network traffic flow than ever before.

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Intro to NFV???

Network function virtualization (NFV) also known as virtual network function (VNF)) offers a new way to design, deploy and manage networking services. NFV decouples the network functions, such as network address translation (NAT), firewalling, intrusion detection, domain name service (DNS), and caching, to name a few, from proprietary hardware appliances so they can run in software.
It’s designed to consolidate and deliver the networking components needed to support a fully virtualized infrastructure – including virtual servers, storage, and even other networks. It utilizes standard IT virtualization technologies that run on high-volume service, switch and storage hardware to virtualize network functions. It is applicable to any data plane processing or control plane function in both wired and wireless network infrastructures.

How a Managed Router Service Can be Deployed with NFV

Sample Network Functions Virtualization NFV deployment

Background

Product development within the telecommunication industry has traditionally followed rigorous standards for stability, protocol adherence and quality, reflected by the use of the term carrier grade to designate equipment demonstrating this reliability.While this model worked well in the past, it inevitably led to long product cycles, a slow pace of development and reliance on proprietary or specific hardware, e.g., bespoke application-specific integrated circuits (ASICs). The rise of significant competition in communication services from fast-moving organizations operating at large scale on the public Internet (such as Google Talk, Skype, Netflix) has spurred service providers to look for ways to disrupt the status quo.

History of Network Functions Virtualization

The concept originated from service providers who were looking to accelerate the deployment of new network services to support their revenue and growth objectives. The constraints of hardware-based appliances led them to applying standard IT virtualization technologies to their networks. To accelerate progress towards this common goal, several providers came together and created the European Telecommunications Standards Institute (ETSI).
The ETSI Industry Specification Group for Network Functions Virtualization (ETSI ISG NFV), a group charged with developing requirements and architecture for virtualization for various functions within telecoms networks, such as standards like NFV MANO. ETSI is also instrumental in collaborative projects like the newly announced OPNFV.

NFV Framework

The NFV framework consists of three main components:

1. Virtualized network functions (VNFs) are software implementations of network functions that can be deployed on a network functions virtualization infrastructure (NFVI).
2. Network functions virtualization infrastructure (NFVI) is the totality of all hardware and software components that build the environment where VNFs are deployed. The NFV infrastructure can span several locations. The network providing connectivity between these locations is considered as part of the NFV infrastructure.
3. Network functions virtualization management and orchestration architectural framework (NFV-MANO Architectural Framework) is the collection of all functional blocks, data repositories used by these blocks, and reference points and interfaces through which these functional blocks exchange information for the purpose of managing and orchestrating NFVI and VNFs.

The building block for both the NFVI and the NFV-MANO is the NFV platform. In the NFVI role, it consists of both virtual and physical processing and storage resources, and virtualization software. In its NFV-MANO role it consists of VNF and NFVI managers and virtualization software operating on a hardware controller. The NFV platform implements carrier-grade features used to manage and monitor the platform components, recover from failures and provide effective security - all required for the public carrier network.

The Benefits of Network Functions Virtualization

NFV virtualizes network services via software to enable operators to:

• Reduce CapEx: reducing the need to purchase purpose-built hardware and supporting pay-as-you-grow models to eliminate wasteful over-provisioning.
• Reduce OpEX: reducing space, power and cooling requirements of equipment and simplifying the roll out and management of network services.
• Accelerate Time-to-Market: reducing the time to deploy new networking services to support changing business requirements, seize new market opportunities and improve return on investment of new services. Also lowers the risks associated with rolling out new services, allowing providers to easily trial and evolve services to determine what best meets the needs of customers.
• Deliver Agility and Flexibility: quickly scale up or down services to address changing demands; support innovation by enabling services to be delivered via software on any industry-standard server hardware.

Distributed NFV

The initial perception of NFV was that virtualized capability should be implemented in data centers. This approach works in many – but not all – cases. NFV presumes and emphasizes the widest possible flexibility as to the physical location of the virtualized functions.
Ideally, therefore, virtualized functions should be located where they are the most effective and least expensive. That means a service provider should be free to locate NFV in all possible locations, from the data center to the network node to the customer premises. This approach, known as distributed NFV, has been emphasized from the beginning as NFV was being developed and standardized, and is prominent in the recently released NFV ISG documents.
For some cases there are clear advantages for a service provider to locate this virtualized functionality at the customer premises. These advantages range from economics to performance to the feasibility of the functions being virtualized.
The first ETSI NFV ISG-approved public multi-vendor proof of concept (PoC) of D-NFV was conducted by Cyan, Inc., RAD, Fortinet and Certes Networks in Chicago in June, 2014, and was sponsored by CenturyLink. It was based on RAD’s dedicated customer-edge D-NFV equipment running Fortinet’s Next Generation Firewall (NGFW) and Certes Networks’ virtual encryption/decryption engine as Virtual Network Functions (VNFs) with Cyan’s Blue Planet system orchestrating the entire ecosystem. RAD's D-NFV solution, a Layer 2/Layer 3 network termination unit (NTU) equipped with a D-NFV X86 server module that functions as a virtualization engine at the customer edge, became commercially available by the end of that month. During 2014 RAD also had organized a D-NFV Alliance, an ecosystem of vendors and international systems integrators specializing in new NFV applications.

In our next blogs we discuss SDN and also what is difference between NFV and SDN. Keep reading and follow blog.

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