WAN SDN
In today's fast-paced digital world, organizations constantly seek ways to optimize their network infrastructure for improved performance, scalability, and cost efficiency. One emerging technology that has gained significant traction is WAN Software-Defined Networking (SDN). By decoupling the control and data planes, WAN SDN provides organizations unprecedented flexibility, agility, and control over their wide area networks (WANs). In this blog post, we will delve into the world of WAN SDN, exploring its key benefits, implementation considerations, and real-world use cases.
WAN SDN is a network architecture that allows organizations to manage and control their wide area networks using software centrally. Traditionally, WANs have been complex and time-consuming to configure, often requiring manual network provisioning and management intervention. However, with WAN SDN, network administrators can automate these tasks through a centralized controller, simplifying network operations and reducing human errors.
1. Enhanced Agility: WAN SDN empowers network administrators with the ability to quickly adapt to changing business needs. With programmable policies and dynamic control, organizations can easily adjust network configurations, prioritize traffic, and implement changes without the need for manual reconfiguration of individual devices.
2. Improved Scalability: Traditional wide area networks often face scalability challenges due to the complex nature of managing numerous remote sites. WAN SDN addresses this issue by providing centralized control, allowing for streamlined network expansion, and efficient resource allocation.
3. Optimal Resource Utilization: WAN SDN enables organizations to maximize their network resources by intelligently routing traffic and dynamically allocating bandwidth based on real-time demands. This ensures that critical applications receive the necessary resources while minimizing wastage.
1. Multi-site Enterprises: WAN SDN is particularly beneficial for organizations with multiple branch locations. It allows for simplified network management across geographically dispersed sites, enabling efficient resource allocation, centralized security policies, and rapid deployment of new services.
2. Cloud Connectivity: WAN SDN plays a crucial role in connecting enterprise networks with cloud service providers. It offers seamless integration, secure connections, and dynamic bandwidth allocation, ensuring optimal performance and reliability for cloud-based applications.
3. Service Providers: WAN SDN can revolutionize how service providers deliver network services to their customers. It enables the creation of virtual private networks (VPNs) on-demand, facilitates network slicing for different tenants, and provides granular control and visibility for service-level agreements (SLAs).
In conclusion, WAN SDN represents a paradigm shift in wide area network management. Its ability to centralize control, enhance agility, and optimize resource utilization make it a game-changer for modern networking infrastructures. As organizations continue to embrace digital transformation and demand more from their networks, WAN SDN will undoubtedly play a pivotal role in shaping the future of networking.
Highlights: WAN SDN
Application Challenges
Compared to a network-centric model, business intent-based WAN networks have great potential. By using a WAN architecture, applications can be deployed and managed more efficiently. However, application services topologies must replace network topologies. Supporting new and existing applications on the WAN is a common challenge for network operations staff. Applications such as these consume large amounts of bandwidth and are extremely sensitive to variations in bandwidth quality. Improving the WAN environment for these applications is more critical due to jitter, loss, and delay.
WAN SLA
In addition, cloud-based applications such as Enterprise Resource Planning (ERP) and Customer Relationship Management (CRM) are increasing bandwidth demands on the WAN. As cloud applications require increasing bandwidth, provisioning new applications and services is becoming increasingly complex and expensive. In today’s business environment, WAN routing and network SLAs are controlled by MPLS L3VPN service providers. As a result, they are less able to adapt to new delivery methods, such as cloud-based and SaaS-based applications.
These applications could take months to implement in service providers’ environments. These changes can also be expensive for some service providers, and some may not be made at all. There is no way to instantiate VPNs independent of underlying transport since service providers control the WAN core. Implementing differentiated service levels for different applications becomes challenging, if not impossible.
Transport Independance: Hybrid WAN
The hybrid WAN concept was born out of this need. An alternative path that applications can take across a WAN environment is provided by hybrid WAN, which involves businesses acquiring non-MPLS networks and adding them to their LANs. Business enterprises can control these circuits, including routing and application performance. VPN tunnels are typically created over the top of these circuits to provide secure transport over any link. 4G/LTE, L2VPN, commodity broadband Internet, and L2VPN are all examples of these types of links.
As a result, transport independence is achieved. In this way, any transport type can be used under the VPN, and deterministic routing and application performance can be achieved. These commodity links can be used to transmit some applications rather than the traditionally controlled L3VPN MPLS links provided by service providers.
SDN and APIs
WAN SDN is a modern approach to network management that uses a centralized control model to manage, configure, and monitor large and complex networks. It allows network administrators to use software to configure, monitor, and manage network elements from a single, centralized system. This enables the network to be managed more efficiently and cost-effectively than traditional networks.
SDN uses an application programming interface (API) to abstract the underlying physical network infrastructure, allowing for more agile network control and easier management. It also enables network administrators to configure and deploy services from a centralized location rapidly. This enables network administrators to respond quickly to changes in traffic patterns or network conditions, allowing for more efficient use of resources.
- Scalability and Automation
SDN also allows for improved scalability and automation. Network administrators can quickly scale up or down the network by leveraging automated scripts depending on its current needs. Automation also enables the network to be maintained more rapidly and efficiently, saving time and resources.
Before you proceed, you may find the following posts helpful:
- WAN Virtualization
- Software Defined Perimeter Solutions
- What is OpenFlow
- SD WAN Tutorial
- What Does SDN Mean
- Data Center Site Selection
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Back to Basics with WAN SDN
A Deterministic Solution
Technology typically starts as a highly engineered, expensive, deterministic solution. As the marketplace evolves and competition rises, the need for a non-deterministic, inexpensive solution comes into play. We see this throughout history. First, mainframes were/are expensive, and with the arrival of a microprocessor personal computer, the client/server model was born. The Static RAM ( SRAM ) technology was replaced with cheaper Dynamic RAM ( DRAM ). These patterns consistently apply to all areas of technology.
Finally, deterministic and costly technology is replaced with intelligent technology using redundancy and optimization techniques. This process is now appearing in Wide Area Networks (WAN). Now, we are witnessing changes to routing space with the incorporation of Software Defined Networking (SDN) and BGP (Border Gateway Protocol). By combining these two technologies, companies can now perform intelligent routing, aka SD-WAN path selection, with an SD WAN Overlay
- A key point: SD-WAN Path Selection
SD-WAN path selection is essential to a Software-Defined Wide Area Network (SD-WAN) architecture. SD-WAN path selection selects the most optimal network path for a given application or user. This process is automated and based on user-defined criteria, such as latency, jitter, cost, availability, and security. As a result, SD-WAN can ensure that applications and users experience the best possible performance by making intelligent decisions on which network path to use.
When selecting the best path for a given application or user, SD-WAN looks at the quality of the connection and the available bandwidth. It then looks at the cost associated with each path. Cost can be a significant factor when selecting a path, especially for large enterprises or organizations with multiple sites.
SD-WAN can also prioritize certain types of traffic over others. This is done by assigning different weights or priorities for various kinds of traffic. For example, an organization may prioritize voice traffic over other types of traffic. This ensures that voice traffic has the best possible chance of completing its journey without interruption.
- Back to basics with DMVPN
Wide Area Network (WAN) DMVPN (Dynamic Multipoint Virtual Private Network) is a type of Virtual Private Network (VPN) that uses an underlying public network, such as the Internet, to transport data between remote sites. It provides a secure, encrypted connection between two or more private networks, allowing them to communicate over the public network without establishing a dedicated physical connection.
Critical Benefits of WAN SDN:
Enhanced Network Flexibility:
WAN SDN enables organizations to dynamically adapt their network infrastructure to meet changing business requirements. Network administrators can quickly respond to network demands through programmable policies and automated provisioning, ensuring optimal performance and resource allocation.
Improved Network Agility:
By separating the control and data planes, WAN SDN allows for faster decision-making and network reconfiguration. This agility enables organizations to rapidly deploy new services, adjust network traffic flows, and optimize bandwidth utilization, ultimately enhancing overall network performance.
Cost Efficiency:
WAN SDN eliminates manual configuration and reduces the complexity associated with traditional network management approaches. This streamlined network management saves costs through reduced operational expenses, improved resource utilization, and increased network efficiency.
Critical Considerations for Implementation:
Network Security:
When adopting WAN SDN, organizations must consider the potential security risks associated with software-defined networks. Robust security measures, including authentication, encryption, and access controls, should be implemented to protect against unauthorized access and potential vulnerabilities.
Staff Training and Expertise:
Implementing WAN SDN requires skilled network administrators proficient in configuring and managing the software-defined network infrastructure. Organizations must train and upskill their IT teams to ensure successful implementation and ongoing management.
Real-World Use Cases:
Multi-Site Connectivity:
WAN SDN enables organizations with multiple geographically dispersed locations to connect their sites seamlessly. Administrators can prioritize traffic, optimize bandwidth utilization, and ensure consistent network performance across all locations by centrally controlling the network.
Cloud Connectivity:
With the increasing adoption of cloud services, WAN SDN allows organizations to connect their data centers to public and private clouds securely and efficiently. This facilitates smooth data transfers, supports workload mobility, and enhances cloud performance.
Disaster Recovery:
WAN SDN simplifies disaster recovery planning by allowing organizations to reroute network traffic dynamically during a network failure. This ensures business continuity and minimizes downtime, as the network can automatically adapt to changing conditions and reroute traffic through alternative paths.
The Rise of WAN SDN
The foundation for business and cloud services are crucial elements of business operations. The transport network used for these services is best efforts, weak, and offers no guarantee of an acceptable delay. More services are being brought to the Internet, yet the Internet is managed inefficiently and cheaply.
Every Autonomous System (AS) acts independently, and there is a price war between transit providers, leading to poor quality of transit services. Operating over this flawed network, customers must find ways to guarantee applications receive the expected level of quality.
Border Gateway Protocol (BGP), the Internet’s glue, has several path selection flaws. The main drawback of BGP is the routing paradigm relating to the path-selection process. BGP default path selection is based on Autonomous System (AS) Path length; prefer the path with the shortest AS_PATH. It misses the shape of the network with its current path selection process. It does not care if propagation delay, packet loss, or link congestion exists. It resulted in long path selection and utilizing paths potentially experiencing packet loss.
Example: WAN SDN with Border6
Border6 is a French company that started in 2012. It offers non-stop internet and an integrated WAN SDN solution, influencing BGP to perform optimum routing. It’s not a replacement for BGP but a complementary tool to enhance routing decisions. For example, it automates changes in routing in cases of link congestion/blackouts.
“The agile way of improving BGP paths by the Border 6 tool improves network stability” Brandon Wade, iCastCenter Owner.
As the Internet became more popular, customers wanted to add additional intelligence to routing. Additionally, businesses require SDN traffic optimizations, as many run their entire service offerings on top of it.
What is non-stop internet?
Border6 offers an integrated WAN SDN solution with BGP that adds intelligence to outbound routing. A common approach when designing SDN in real-world networks is to prefer that SDN solutions incorporate existing field testing mechanisms (BGP) and not reinvent all the wheels ever invented. Therefore, the border6 approach to influence BGP with SDN is a welcomed and less risky approach to implementing a greenfield startup. In addition, Microsoft and Viptela use the SDN solution to control BGP behavior.
Border6 uses BGP to guide what might be reachable. Based on various performance metrics, they measure how well paths perform. They use BGP to learn the structure of the Internet and then run their algorithms to determine what is essential for individual customers. Every customer has different needs to reach different subnets. Some prefer costs; others prefer performance.
They elect several interesting “best” performing prefixes, and the most critical prefixes are selected. Next, they find probing locations and measure the source with automatic probes to determine the best path. All these tools combined enhance the behavior of BGP. Their mechanism can detect if an ISP has hardware/software problems, drops packets, or rerouting packets worldwide.
Thousands of tests per minute
The Solution offers the best path by executing thousands of tests per minute and enabling results to include the best paths for packet delivery. Outputs from the live probing of path delays and packet loss inform BGP on which path to route traffic. The “best path” is different for each customer. It depends on the routing policy the customer wants to take. Some customers prefer paths without packet loss; others wish to cheap costs or paths under 100ms. It comes down to customer requirements and the applications they serve.
BGP – Unrelated to Performance
Traditionally, BGP gets its information to make decisions based on data unrelated to performance. Broder 6 tries to correlate your packet’s path to the Internet by choosing the fastest or cheapest link, depending on your requirements.
They are taking BGP data service providers and sending them as a baseline. Based on that broad connectivity picture, they have their measurements – lowest latency, packets lost, etc.- and adjust the data from BGP to consider these other measures. They were, eventually, performing optimum packet traffic forwarding. They first look at Netflow or Sflow data to determine what is essential and use their tool to collect and aggregate the data. From this data, they know what destinations are critical to that customer.
BGP for outbound | Locator/ID Separation Protocol (LISP) for inbound
Border6 products relate to outbound traffic optimizations. It can be hard to influence inbound traffic optimization with BGP. Most AS behave selfishly and optimize the traffic in their interest. They are trying to provide tools that help AS optimize inbound flows by integrating their product set with the Locator/ID Separation Protocol (LISP). The diagram below displays generic LISP components. It’s not necessarily related to Border6 LISP design.
LISP decouples the address space so you can optimize inbound traffic flows. Many LISP uses cases are seen with active-active data centers and VM mobility. It decouples the “who” and the “where,” which allows end-host addressing not to correlate with the actual host location. The drawback is that LISP requires endpoints that can build LISP tunnels.
Currently, they are trying to provide a solution using LISP as a signaling protocol between Border6 devices. They are also working on performing statistical analysis for data received to mitigate potential denial-of-service (DDoS) events. More DDoS algorithms are coming in future releases.
Conclusion:
WAN SDN is revolutionizing how organizations manage and control their wide area networks. WAN SDN enables organizations to optimize their network infrastructure to meet evolving business needs by providing enhanced flexibility, agility, and cost efficiency.
However, successful implementation requires careful consideration of network security, staff training, and expertise. With real-world use cases ranging from multi-site connectivity to disaster recovery, WAN SDN holds immense potential for organizations seeking to transform their network connectivity and unlock new opportunities in the digital era.
Summary: WAN SDN
In today’s digital age, where connectivity and speed are paramount, traditional Wide Area Networks (WANs) often fall short of meeting the demands of modern businesses. However, a revolutionary solution that promises to transform how we think about and utilize WANs has emerged. Enter Software-Defined Networking (SDN), a paradigm-shifting approach that brings unprecedented flexibility, efficiency, and control to WAN infrastructure.
Understanding SDN
At its core, SDN is a network architecture that separates the control plane from the data plane. By decoupling network control and forwarding functions, SDN enables centralized management and programmability of the entire network, regardless of its geographical spread. Traditional WANs relied on complex and static configurations, but SDN introduced a level of agility and simplicity that was previously unimaginable.
Benefits of SDN for WANs
Enhanced Flexibility
SDN empowers network administrators to dynamically configure and customize WANs based on specific requirements. With a software-based control plane, they can quickly implement changes, allocate bandwidth, and optimize traffic routing, all in real time. This flexibility allows businesses to adapt swiftly to evolving needs and drive innovation.
Improved Efficiency
By leveraging SDN, WANs can achieve higher levels of efficiency through centralized management and automation. Network policies can be defined and enforced holistically, reducing manual configuration efforts and minimizing human errors. Additionally, SDN enables the intelligent allocation of network resources, optimizing bandwidth utilization and enhancing overall network performance.
Enhanced Security
Security threats are a constant concern in any network infrastructure. SDN brings a new layer of security to WANs by providing granular control over traffic flows and implementing sophisticated security policies. With SDN, network administrators can easily monitor, detect, and mitigate potential threats, ensuring data integrity and protecting against unauthorized access.
Use Cases and Implementation Examples
Dynamic Multi-site Connectivity
SDN enables seamless connectivity between multiple sites, allowing businesses to establish secure and scalable networks. With SDN, organizations can dynamically create and manage virtual private networks (VPNs) across geographically dispersed locations, simplifying network expansion and enabling agile resource allocation.
Cloud Integration and Hybrid WANs
Integrating SDN with cloud services unlocks a whole new level of scalability and flexibility for WANs. By combining SDN with cloud-based infrastructure, organizations can easily extend their networks to the cloud, access resources on demand, and leverage the benefits of hybrid WAN architectures.
Conclusion:
With its ability to enhance flexibility, improve efficiency, and bolster security, SDN is ushering in a new era for Wide-Area Networks (WANs). By embracing the power of software-defined networking, businesses can overcome the limitations of traditional WANs and build robust, agile, and future-proof network infrastructures. It’s time to embrace the SDN revolution and unlock the full potential of your WAN.