Grasping the differences between underlay and overlay networks is essential for navigating the complexities of modern networking. Underlay networks form the physical backbone of data transmission, providing the necessary infrastructure for communication. In contrast, overlay networks add a virtual layer on top, offering enhanced capabilities such as scalability, flexibility, and improved security.
These networks work in tandem, yet each plays a unique role in ensuring efficient and robust network performance. Understanding how these networks differ and complement each other is vital for businesses and IT professionals to optimize network architecture and achieve strategic goals. Interact with Managed IT Services Denver experts to choose the right network for your business.
In this blog, we will explore the critical differences between underlay and overlay networks, providing insights into their roles and advantages.
What is an Underlay Network?
An underlay network refers to the physical infrastructure that forms the foundation of a network. It consists of hardware components like routers, switches, cables, protocols, and technologies that enable data transmission at a basic level. The underlay network is responsible for handling the actual movement of data packets across the network.
What is an Overlay Network?
An overlay network is a virtual network built on top of the underlay network. It creates a logical network that provides additional features and functionalities by abstracting the underlying physical infrastructure. Overlay networks enable more advanced networking capabilities, such as virtualization, segmentation, and enhanced security.
9 Differences Between Underlay and Overlay Networks
1.Scalability
Underlay networks serve as the physical foundation for communication between devices. However, they can be challenging to scale as they require significant changes to the underlying infrastructure to accommodate growth.
On the other hand, overlay networks create a virtual layer on top of the existing infrastructure, allowing for greater scalability as the limitations of the underlying network do not constrain them. Adding new nodes or connections to the overlay network without directly impacting the underlying infrastructure can achieve scalability more efficiently.
2. Related Protocols
Underlay networks usually use protocols like Ethernet, TCP/IP, and MPLS (Multiprotocol Label Switching) to establish connections and route traffic within the physical network infrastructure.
Conversely, overlay networks use additional protocols, such as Virtual Extensible LAN (VXLAN) or Generic Routing Encapsulation (GRE), to create virtualized network layers on the existing infrastructure. These protocols are crucial in determining how data is transmitted, encapsulated, and delivered across different network environments, ultimately influencing the functionality and performance of underlay and overlay networks.
3. Deployment Time
Underlay networks are typically provisioned and managed directly by the network operator, which can result in longer deployment times due to the need for physical infrastructure setup and configuration.
On the other hand, overlay networks can be deployed more quickly as they operate on top of existing networks without requiring significant changes to the underlying infrastructure. This agility in deployment makes overlay networks a popular choice for organizations seeking rapid network expansion or adaptation to changing requirements.
4.Traffic Flow
In an underlay network, traffic is routed based on the physical infrastructure of the network. This means that the underlying network determines how data is transmitted from one point to another.
In contrast, in an overlay network, traffic is routed based on logical paths separate from the physical network infrastructure. This allows more flexibility in managing and optimizing data flow because the overlay network can adjust to changing conditions and requirements without directly affecting the underlying physical network.
5.Data Transmission
Underlay networks are the physical infrastructure that carries network traffic, including cables and routers. They focus on efficiently routing data packets through the physical network to ensure reliable connectivity.
On the other hand, overlay networks are built on top of existing networks to provide additional services or functions. They add a virtualization layer to offer features such as enhanced security, improved scalability, or specialized routing protocols for data transmission.
Also Read: Tips for Secure Data Transfer
In underlay networks, packet encapsulation occurs at the network layer. Each packet is wrapped in a header containing routing information to facilitate communication within the network infrastructure. This process adds overhead to data transmission as the headers increase the size of each packet.
In overlay networks, packet encapsulation occurs at a higher layer, typically at the application level. This allows for greater flexibility and customization in how packets are handled and routed but can also introduce additional overhead due to the increased complexity of managing multiple encapsulation layers.
7. Multi-Path Forwarding
In underlay networks, multi-path forwarding involves distributing traffic across multiple physical paths to improve network efficiency and reliability. This is typically achieved through protocols like Equal-Cost Multi-Path (ECMP) routing.
On the other hand, in overlay networks, multi-path forwarding is implemented at a higher level. Data packets are encapsulated and forwarded through virtual paths that may not align with the underlying physical network topology.
8. Multitenancy
In an underlay network, multitenancy refers to the ability of multiple tenants to share physical networking infrastructure while maintaining isolation at the network level. Each tenant has dedicated resources and network segments within the shared infrastructure.
On the other hand, in an overlay network, multitenancy is achieved through virtualization. Tenants can create their own isolated virtual networks on top of a shared physical network. This allows for greater flexibility and scalability but may introduce additional complexity in managing the overlay network architecture.
9. Packet Control
In an underlay network, packet forwarding decisions are determined by the physical infrastructure of the network. Routers use metrics like latency and bandwidth to find the best path for the packets.
On the other hand, overlay networks implement packet control at a higher level by adding logical layers to existing networks, enabling specific functionalities such as virtualization or encryption.
Conclusion
Understanding the differences between underlay and overlay networks is essential when designing and managing network infrastructures. Underlay networks provide the physical connectivity necessary for overall network performance, ensuring reliable and high-performance connectivity. Overlay networks, on the other hand, offer enhanced flexibility, segmentation, and advanced features by operating on top of the existing infrastructure. They enable sophisticated virtualized environments and dynamic network management. By partnering with Cybersecurity Denver team, organizations can create robust and adaptable networking solutions to meet their specific needs.