What Is Access Layer and How to Choose the Right Access Switch?

In the intricate world of networking, the access layer stands as the gateway to a seamless connection between end-user devices and the broader network infrastructure. At the core of this connectivity lies the access layer switch, a pivotal component that warrants careful consideration for building a robust and efficient network. This article explores the essence of the access layer, delves into how it operates, distinguishes access switches from other types, and provides insights into selecting the right access layer switch.

What is the Access Layer?

The Access Layer, also known as the Edge Layer, in network infrastructure is the first layer within a network topology that connects end devices, such as computers, printers, and phones, to the network. It is where users gain access to the network. This layer typically includes switches and access points that provide connectivity to devices. The Access Layer switches are responsible for enforcing policies such as port security, VLAN segmentation, and Quality of Service (QoS) to ensure efficient and secure data transmission.

For instance, our S5300-12S 12-Port Ethernet layer 3 switch would be an excellent choice for the Access Layer, offering robust security features, high-speed connectivity, and advanced QoS policies to meet varying network requirements.

Access Layer Switch

What is Access Layer Used for?

The primary role of the access layer is to facilitate communication between end devices and the rest of the network. This layer serves as a gateway for devices to access resources within the network and beyond. Key functions of the access layer include:

Device Connectivity

The access layer ensures that end-user devices can connect to the network seamlessly. It provides the necessary ports and interfaces for devices like computers, phones, and printers to establish a connection.

VLAN Segmentation

Virtual LANs (VLANs) are often implemented at the access layer to segment network traffic. This segmentation enhances security, manageability, and performance by isolating traffic into logical groups.

Security Enforcement

Security policies are enforced at the access layer to control access to the network. This can include features like port security, which limits the number of devices that can connect to a specific port.

Quality of Service (QoS)

The access layer may implement QoS policies to prioritize certain types of traffic, ensuring that critical applications receive the necessary bandwidth and minimizing latency for time-sensitive applications.

What is the Role of An Access Layer Switch?

Access switches serve as the tangible interface at the access layer, tasked with linking end devices to the distribution layer switches while guaranteeing the delivery of data packets to those end devices. In addition to maintaining a consistent connection for end users and the higher-level distribution and core layers, an access switch must fulfill the demands of the access layer. This includes streamlining network management, offering security features, and catering to various specific needs that differ based on the network context.

Factors to Consider When Selecting Access Layer Switches

Choosing the right access layer switches is crucial for creating an efficient and reliable network. Consider the following factors when selecting access layer switches for your enterprise:

  • Port Density

Evaluate the number of ports required to accommodate the connected devices in your network. Ensure that the selected switch provides sufficient port density to meet current needs and future expansion.

  • Speed and Bandwidth

Consider the speed and bandwidth requirements of your network. Gigabit Ethernet is a common standard for access layer switches, but higher-speed options like 10 Gigabit Ethernet may be necessary for bandwidth-intensive applications.

  • Power over Ethernet (PoE) Support

If your network includes devices that require power, such as IP phones and security cameras, opt for switches with Power over Ethernet (PoE) support. PoE eliminates the need for separate power sources for these devices.

  • Manageability and Scalability

Choose switches that offer easy management interfaces and scalability features. This ensures that the network can be efficiently monitored, configured, and expanded as the organization grows.

  • Security Features

Look for switches with robust security features. Features like MAC address filtering, port security, and network access control (NAC) enhance the overall security posture of the access layer.

  • Reliability and Redundancy

Select switches with high reliability and redundancy features. Redundant power supplies and link aggregation can contribute to a more resilient access layer, reducing the risk of downtime.

  • Cost-Effectiveness

Consider the overall cost of the switch, including initial purchase cost, maintenance, and operational expenses. Balance the features and capabilities of the switch with the budget constraints of your organization.

  • Compatibility with Network Infrastructure

Ensure that the chosen access layer switches are compatible with the existing network infrastructure, including core and distribution layer devices. Compatibility ensures seamless integration and optimal performance.

Related Article:How to Choose the Right Access Layer Switch?

Conclusion

In conclusion, the access layer is a critical component of network architecture, facilitating connectivity for end-user devices. Choosing the right access layer switches is essential for building a reliable and efficient network. Consider factors such as port density, speed, PoE support, manageability, security features, reliability, and compatibility when selecting access layer switches for your enterprise. By carefully evaluating these factors, you can build a robust access layer that supports the connectivity needs of your organization while allowing for future growth and technological advancements.

What is Core Layer and How to Choose the Right Core Switch?

What is Core Layer?

The Core Layer in networking serves as the backbone of a hierarchical network design, forming a critical component within the three-layer model alongside the Access and Distribution layers. Situated at the center of network architecture, the Core Layer is designed for high-speed, high-capacity packet switching, ensuring swift and efficient transport of data across the entire network.

Unlike the Distribution Layer, the Core Layer typically focuses on rapid data transfer without applying extensive processing or policy-based decision-making. Its primary objective is to facilitate seamless and fast communication between different parts of the network.

Duty of Core Switches

In the enterprise hierarchical network design, the core layer switch is the topside one, which is relied on by the other access and distribution layers. It aggregates all the traffic flows from distribution layer devices and access layer devices, and sometimes core switches need to deal with external traffic from other egresses devices. So it is important for core switches to send large amounts of packets as much as possible. The core layer always consists of high-speed switches and routers optimized for performance and availability.

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Figure 1: Core Switches in the three-tier architecture

Located at the core layer of enterprise networking, a core layer switch functions as a backbone switch for LAN access and centralizes multiple aggregation devices to the core. In these three layers, core switches require most highly in the switch performance. They are usually the most powerful, in terms of forwarding large amounts of data quickly. For most of the cases, core switches manage high-speed connections, such as 10G Ethernet, 40G Ethernet or 100G Ethernet. To ensure high-speed traffic transfer, core switches should not perform any packet manipulation such as Inter-Vlan routing, Access Lists, etc., which are performed by distribution devices.

Note: In small networks, it is often the case to implement a collapsed core layer, combining the core layer and the distribution layer into one as well as the switches. More information about the collapsed core is available in How to Choose the Right Distribution Switch?

Factors to Consider When Choosing Core Switches for Enterprises

Simply put, core layer switches are generally layer 3 switches with high performance, availability, reliability, and scalability. Except for considering the basic specifications like port speed and port types, the following factors should be considered when choosing core switches for an enterprise network design.

Performance

The packet forwarding rate and switching capacity matter a lot to the core switch in enterprise networking. Compared with the access layer switches and distribution switches, core switches must provide the highest forwarding rate and switching capacity as much as possible. The concrete forwarding rate largely depends on the number of devices in the network, the core switches can be selected from the bottom to the top based on the distribution layer devices.

For instance, network designers can determine the necessary forwarding rate of core switches by checking and examining the various traffic flow from the access and distribution layers, then identify one or more appropriate core switches for the network.

Redundancy

Core switches pay more attention to redundancy compared with other switches. Since the core layer switches carry much higher workloads than the access switches and distribution switches, they are generally hotter than the switches in the other two layers, the cooling system should be taken into consideration. As often the case, core layer switches are generally equipped with redundant cooling systems to help the switches cooling down while they are running.

The redundant power supply is another feature that should be considered. Imagine that the switches lose power when the networking is running, the whole network would shut down when you are going to perform a hardware replacement. With redundant power supplies, when one supply fails, the other one will instantly start running, ensuring the whole network unaffected by the maintenance.

FS provides switches with hot-swappable fans and power supply modules for better redundancy.

Reliability

Typically core switches are layer 3 switches, performing both switching and routing functions. Connectivity between a distribution and core switches is accomplished using layer 3 links. Core switches should perform advanced DDoS protection using layer 3 protocols to increase security and reliability. Link aggregation is needed in core switches, ensuring distribution switches delivering network traffic to the core layer as efficiently as possible.

Moreover, fault tolerance is an issue to consider. If a failure occurs in the core layer switches, every user would be affected. Configurations such as access lists and packet filtering should be avoided in case that network traffic would slow down. Fault-tolerant protocols such as VRRP and HSRP is also available to group the devices into a virtual one and ensure the communication reliability in case one physical switch breaks down. What’s more, when there are more than one core switches in some enterprise networks, the core switches need to support functions such as MLAG to ensure the operation of the whole link if a core switch fails.

QoS Capability

QoS is an essential service that can be desired for certain types of network traffic. In today’s enterprises, with the growing amount of data traffic, more and more voice and video data are required. What if network congestion occurs in the enterprise core? The QoS service will make sense.

With the QoS capability, core switches are able to provide different bandwidth to different applications according to their various characteristics. Compared with the traffic that is not so sensitive about time such as E-mail, critical traffic sensitive to time should receive higher QoS guarantees so that more important traffic can pass first, with the high forwarding of data and low package loss guaranteed.


As you can see from the contents above, there are many factors that determine what enterprise core switches are most suitable for your network environment. In addition, you may need a few conversations with the switch vendors and know what specific features and services they can provide so as to make a wise choice.


Related Articles:

How to Choose the Right Access Layer Switch?

How to Choose the Right Core Switch?