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UNRAVELLING THE ONION OF INDUSTRIAL NETWORK SWITCH LAYERS

#2023, #switches, #witchos

December 5, 2023

Network switches operate on different layers of the OSI model of networking, with each one representing a different scope of functionality suitable for different industrial applications. In this article, we’ll go over the different layers and associated functionalities, and help you identify the best network switch for your solution.

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Teltonika Networks recently announced that starting in January 2024, it will be cutting the average price of its network switches by an average of 30%. This represents our commitment to rapidly expand and grow in the global industrial network switch market.

This initiative has many layers, which is very on-theme for network switches. You see, any given switch operates in one of the 7 layers of the Open Systems Interconnection (OSI) model of networking. A network switch operating in any of these 7 layers means it has functionality that falls under that layer.

But as any seasoned network engineer can tell you, it’s not quite as clear-cut as just having 7 neat categories. Switches generally operate on 5 out of the 7 layers, with Layers 5 and 6 staying out of the picture. And there is even a secret layer somewhere in between!


Indeed, switch layers are much like the layers of an onion: if you’re not careful, they might just make you cry. To ensure that doesn’t happen, let’s go over the different layers and associated functionalities, and learn when should you deploy a network switch operating in that layer.


Note that as we go up the layers, factors such as device sophistication, price, and performance do scale. Higher-level switches are more expensive, consume more power, require more complex configuration, and typically provide slower performance when it comes to raw data forwarding. On the flip side, they offer greater security and intelligence that some solutions simply can’t do without.

Layer 1: physical

The most basic level of network switches, the physical layer, covers the basics. A switch in this layer is an unmanaged switch capable of transferring data, including encoding, signalling, transmitting, and receiving it, but cannot manage the traffic in any way. In other words, a Layer 1 network switch can be deployed when you need a hub without any filtering or processing capabilities.

The simplicity of Layer 1 switches keeps them affordable and easy to deploy. Their data transmission happens at wire speed, but circuit switching configuration can help optimise this speed if needed.

If simple data transference without network management is sufficient for your solution, a Layer 1 switch is perfectly good enough.

Layer 2: data link

Layer 2 switches are your typical network switches, as this is the most common layer. And fortunately, they have a bit more brains to them. Known as managed switches, these are capable of identifying end devices and use Ethernet frames and MAC addresses for correctly processing and forwarding data.

They are also capable of VLAN tagging, traffic prioritisation, and MAC address filtering, and are able to efficiently manage the flow of data across a network by switching data frames from one LAN port to another. Importantly, each port on a Layer 2 switch is a separate collision domain. This significantly reduces the risk of network traffic collisions, resulting in smoother data flow.

If you need a device for managing your network’s data quickly and without much granularity, Layer 2 is the layer for you.

Layer 3: network

Layer 3 managed switches begin to overlap with routers, as they boast both switching and routing capabilities, including support of IP routing between configured VLANs as well as advanced and dynamic support of other routing protocols, like RIP, OSPF and BGP, for exchanging route information between networks. Unlike routers, however, they can only support a single type of network.

On top of better network segmentation and traffic management, Layer 3 switches also offer high throughput, low latency, Quality of Service (QoS), and robust security features, including ACLs, firewall capabilities, and deep packet inspection.

If you need your network switch to have basic routing capabilities, but more than just static routing, Layer 3 is the way to go.

Layer 4: transport

Layer 4 network switches, known as multi-layer switches, offer complex network management capabilities. They can identify the application protocol included in each packet (HTTP, FTP, etc.) and use this information to decide which higher-level software is most appropriate for that packet.

A Layer 4 switch is also capable of determining to which server any given query should be sent to (depending on server loads), identifying offline servers, and TCP/UDP session establishment and termination.

Layer 4 switches are a good choice when you need more control over your network traffic than Layer 3 switches can provide, striking a balance between performance and functionality.

Layer 7: application

As Layers 5 and 6 aren’t relevant to the world of network switches, let’s skip straight to the final, ultimate layer. Layer 7 switches provide faster forwarding and routing decisions based on more granular information and are capable of intelligent inspection of data within each packet.

For example, a Layer 7 network switch can recognise application-level transactions based on URLs and other installation or configuration-specific techniques. It can then use the information within cookies, HTTP headers, or URL strings to inform its own forwarding decisions.

Other features of Layer 7 include enabling, disabling, mirroring, assignment, and aggregation of ports, VLAN configuration, SNMP monitoring, and many others.

Layer 7 network switches are often used in complex environments requiring high-level data routing decisions, such as data centres, cloud services, and telecom services.

On which layers do Teltonika Networks industrial switches operate?

Presently, the TSW series of Teltonika Networks industrial switches operate on two different layers. Our 8 unmanaged switches operate on Layer 2, providing simple data transference. They aren’t all the same, of course – different products offer different value to any given networking solution, such as port number and type, the inclusion or exclusion of Power over Internet (PoE) functionality, and so on.

We also have 2 managed switches operating on Layer 2, except their scope of features goes beyond that. These devices also feature a number of Layer 3 features, including static routing for basic traffic routing between different subnets or VLANs, port control capabilities, advanced VLAN support, and support of key protocols such as Profinet, SNMP, LLDP, and Ethernet/IP. Not only that, but they run on a custom operating system developed specifically for our managed switches: WitchOS.

The magic of WitchOS

WitchOS (Switch without the S, in case you’re wondering) opens the door to a new world of value to networking solutions deploying managed switches. While Teltonika Networks only has managed switches operating in Layer 2 (plus!) at the moment, rest assured that WitchOS will be just as magical when products in higher layers do become available (we’re working on it!).

So, what benefits does WitchOS actually bring to the networking table?

Imagine your solution involves a complex network of end devices. PLCs, HMIs, panels, sensors – the whole package. Maintaining a clear understanding of your network’s topology is essential for efficient operations and troubleshooting. This necessitates support of the Link Layer Discovery Protocol (LLDP).

WitchOS supports LLDP, allowing you to effortlessly integrate new end devices and identify them whenever any issues arise. If one end device malfunctions, LLDP lets you quickly pinpoint its exact location and relationships with other devices in your topology.

Another key protocol supported by WitchOS is Profinet, which is used for high-speed, deterministic data exchange between controllers, such as PLCs, and other end devices. This is integral for industrial operations that rely on instantaneous M2M data exchange, such as complex and high-precision manufacturing lines.

Apart from protocol support, WitchOS incorporates many beloved features from RutOS, the operating system of Teltonika Networks routers and gateways – so long as they’re relevant to network switch use. This includes excellent UI and specialised pages for a long list of network control functions and configurations that will assist you in efficiently staying on top of your network’s status, performance, and operations.

The right layer for your solution

Choosing the right switch layer for your networking solution depends on its needs. Consider the size and complexity of your network, as well as security and routing needs.

If you’re unsure which layer is right for you, click the button below to have a chat with one of our sales representatives!

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