What is a Core Switch | Functions and Difference over Normal Switch

What is a core switch and how it works? This article builds the basics of this kind of switch for the ones who don't know anything about it. 

What is a Core Switch?

It is a powerful backbone switch in the center of the network core layer, which centralizes multiple aggregation switches to the core and implements LAN routing. The normal edge switch is in the access layer to directly connect multiple end devices. In these switches, the data routed and switched by the core switch is sent to the network's lower levels, such as the distribution and access layers. 

This technique of data routine means that the whole network's performance is dependent on the data routed and switched by the core switch. Multiple data switches are typically employed at the core layer of a network to route a huge volume of data to the levels in the hierarchy. Another rationale for utilizing numerous data switches at the core layer is to reduce data packet congestion. If data packets are overcrowded at the distribution and access levels, data back-flow may trigger a core layer problem. That is why a variety of high-capacity core switches are available in the market right now.

Advantages of Core Switch:

There are numerous advantages of such switches, one is that the classic switch's outbound port cache mechanism has been replaced with a distributed cache design in the core switch. Its cache is substantially bigger than that of a standard switch, with a cache size of more than 1G compared to 2-4m for a standard switch. Because each port has a burst traffic buffer capacity of 200ms under the condition of 10G full line speed, the large cache capacity can still ensure zero packet loss in network forwarding in the case of burst traffic, which is only suitable for data centers with a large number of servers and burst traffic.

Another advantage here is that high-density application scheduling and surge-type burst buffering are present in such switches. Ordinary switches, on the other hand, are designed for interconnection and intercommunication and cannot provide service identification and control. Large services cannot reply rapidly with minimal packet loss, and hence business continuity cannot be assured.

The network equipment in the data center must have high manageability, security, and reliability, thus the switches in the data center must also enable virtualization. To break down boundaries between physical structures, virtualization transforms physical resources into conceptually controlled resources which are only possible with the core switches. Moreover, the initial standard for constructing a two-layer network in a data center is the FTP protocol, however, its inherent flaws are as follows: STP operates by port blocking, and redundant connections do not execute data forwarding, resulting in a waste of broadband resources. Additionally, because STP only has a spanning tree, data packets must be forwarded by the root bridge to reach them, affecting the overall network's forwarding efficiency. This all can be avoided in core switches as compared to ordinary ones. 

Another advantage here with the core switches is link aggregation which is the combining of two or more data channels into a single channel that appears as a higher-bandwidth logical link. In general, link aggregation is used to join one or more devices with large bandwidth requirements, such as servers or server farms linked to a backbone network. It may be used to increase network bandwidth and connection dependability.

Difference between a Normal Switch and Core Switch:

Aside from the advantages and explanation of What is core switch, we need to learn how this switch is different from the others. The access layer is the section of the network that directly deals with users' network connections or access, while the distribution layer or aggregation layer is the part of the network that sits between the access layer and the core layer. Because the access layer switch's function is to allow end-users to connect to the network, it must be low-cost and have a high port density.

The core switch and its layer are the most important portion of the entire network because its primary function is to create an optimal and dependable backbone transmission structure. This is done via a high-speed communication forwarding route and as a result, the core layer switch application has improved in terms of reliability, performance, and throughput. 

The major difference between core switches and ordinary (aggregation) switches is their network performance. Core switches as expected are designed to be quicker than aggregation switches. This is due to the core switch's connections with several aggregation switches.

Another major difference is that the data from all the other levels including the distribution and access layers, is collected by the core switches. This type of switch also handles external network traffic. The core-type layer is made up of multiple core switches that operate at high speeds. Network aggregation switches, on the other hand, connect many networks over a single link. As a result, it increases the network's bandwidth.

This article explained the question of what is core switch along with other fundamental differences as compared to normal ones. Hope this helps your understanding.