Network Virtualization Overlay vs Underlay Networks
Network virtualization is a popular method for creating logical networks that are decoupled from the underlying physical infrastructure. It enables businesses to build more scalable, flexible, and efficient networks that can meet the increasing demands of modern applications.
There are two main approaches to network virtualization: overlay and underlay networks. In this blog post, we will explore both of these approaches to help you understand their differences and make an informed decision on which one suits your needs.
What are Underlay Networks?
Underlay networks are the traditional networks that use physical infrastructure for forwarding traffic. The physical infrastructure includes switches, routers, firewalls, and other networking components that manage the actual transmission of data packets. These networks are responsible for providing connectivity and transport services to the virtual networks that run on top of them.
What are Overlay Networks?
Overlay networks create logical networks that are isolated from the underlying physical infrastructure. They use virtual network components like virtual switches, routers, and tunnels to transmit data packets between endpoints. These components are software-based and run on top of the underlying physical network infrastructure. Overlay networks appear as if they are running on their own dedicated physical network.
Comparison: Overlay vs. Underlay Networks
| Criteria | Overlay Network | Underlay Network |
|---|---|---|
| Scalability | Highly scalable | Limited scalability |
| Performance | Slightly lower performance | Highest possible performance |
| Flexibility | Highly flexible | Limited flexibility |
| Complexity | Moderate Complexity | High Complexity |
As you can see from the table, overlay networks provide a high level of scalability and flexibility, which makes them ideal for large-scale virtual networks. On the other hand, underlay networks offer better performance due to their direct interaction with the physical infrastructure. However, underlay networks are limited in scalability and are less flexible than overlay networks.
In conclusion, selecting the best network virtualization approach depends on your business needs. If you require a highly scalable and flexible network for your virtual infrastructure, then overlay networks are the better option. However, if you need to prioritize performance over scalability and flexibility, then underlay networks are the way to go.
References
- Jain, S. et al., 2013. B4: Experience with a Globally-Deployed Software Defined WAN, ACM SIGCOMM Conference, pp. 3-14.
- Morad, S., Modadugu, N., & Yavatkar, R. (2013). Network virtualization: a view from a network operator. ACM SIGCOMM Computer Communication Review, 43(4), 21-27.
- Zhao, Y., Wang, M., Li, F., Li, B., & Li, Y. (2016). A survey of software-defined network and network function virtualization: architecture, protocols, and applications. IEEE Communications Surveys & Tutorials, 18(1), 535-561.