Fibre Channel Switch vs Ethernet Switch: What Are the Differences?

Some IT architects are apt to be indecisive when selecting Fiber Channel (FC) switches or Ethernet switches for their data center infrastructure. Or they may have invested in Fibre Channel networking before, but consider whether to stay with FC or make the move to Ethernet. This article will illustrate what Fibre Channel switch and Ethernet switch are, and make a detailed comparison between the two.

What Is Fibre Channel Switch?

Fibre Channel (FC), designed for storage area networks (SANs), is a high-speed network technology used to connect computer data storage to servers, providing point-to-point, switched and loop interfaces to deliver in-order and lossless raw block data.

In the switched fabric topology that requires switches, all the devices are connected and communicated via switches. Fibre Channel SAN switches serve the same general purpose as any other network switches: automatically connecting senders and receivers, playing an important role in interconnecting multiple storage ports and servers. Compatible with Fibre Channel Protocol (FCP), fibre channel switches feature high-performance, low-latency, high-availability, and lossless data transmission in a Fibre Channel fabric topology and are specifically designed to handle heavy transaction loads over high-performance Fibre Channel networks.

A fibre channel switch connects to storage and servers.

How does Fibre Channel Switch Work?

An FC switch eliminates the need for every server to have a direct connection to every storage array and thus reduces complexity. Although Fibre Channel supports point-to-point connections in which a server physically access the attached storage directly without an FC switch, this architecture doesn't scale well. An FC switch solves this problem by acting as an intermediary between servers and storage. Servers and storage devices are both attached to an FC switch. When a server needs to access a storage device, the FC switch directs the request to the appropriate storage device.

FC switches work to bridge servers and storage.

What Is Ethernet Switch?

The word "Ethernet" is not unfamiliar to you compared with "Fibre Channel". IEEE defines Ethernet as protocol 802.3. Jargon aside, Ethernet refers to the technology of connecting computers and other devices via a protocol, which is most commonly used in wired local area networks (LANs).

When deploying an Ethernet network, Ethernet switches are indispensable certainly. Ethernet switches are the basic building blocks of networks, which bridge Ethernet devices together. Normally speaking, a LAN switch is likely to be an Ethernet-based switch with copper or optical interfaces, the port number of which vary. The speed that the switches can support may be 1GbE, 25GbE, 40GbE, 100GbE or even higher.

Ethernet switches connect to multiple devices like computers, routers, etc.

Fibre Channel vs Ethernet Switch: What Are the Differences?

As mentioned before, Fibre Channel switches are mainly used in SANs whilst Ethernet switches are mostly applied in LANs. This part will further illustrate the differences between Fibre Channel vs Ethernet Switch in four main aspects: application, reliability, transmission speed, and cost.

Application

Ethernet switches allow a large variety of devices to communicate with one another using Ethernet packets. Ethernet network can accommodate devices such as PCs, tablets and IoT devices. While FC switches are used only for connecting servers to storage arrays, not for general-purpose network communications, nor do FC devices require an IP address.

Reliability

Fibre Channel switches operate lossless without dropping a single frame, and all the data frames are transmitted in order.This is because FC switches will stop sending frames lest they are dropped when congesting to other devices. Ethernet switches may be at the risk of dropping frames, which starts when congested and only relies on upper layers, TCP (Transmission Control Protocol) for example, to make sure everything keeps working.

Transmission Speed

The maximum data rate of Fibre Channel switch has evolved up to 256GFC, with 8GFC, 16GFC, 32GFC, 64GFC, and 128GFC versions available, according to the Fibre Channel Speedmap illustrated by Fibre Channel Industry Association. Ethernet switch transmission speeds range from Fast Ethernet, Gigabit Ethernet, 10 Gigabit Ethernet to 100/400GbE.

A majority of Fibre Channel networks these days are 8Gbps or 16Gbps, while most Ethernet configurations are typically 1Gbps/10Gbps for home networks and 25G/40Gbps/100Gbps for data center networks. Generally speaking, 8GFC networks run close to the effective rate of 10GbE, so the difference is nearly negligible. And 16GFC is pretty much faster than 10GbE or performance is sometimes at least a tie. In a word, the practical transmission speed of each will be decided by the specific working environment.

Cost

In most cases, Ethernet switches are much cheaper than Fibre Channel switches. However, Fibre Channel is mainly used in the data center SAN environment, while Ethernet can be found in different kinds of networks: from small homes, big offices to large-scale data centers. For the employment of a data center, 8Gbps FC is generally less expensive than 10Gbps Ethernet and 16GFC costs about the same as 10GbE. When it comes to enterprises, many already have invested large amounts of time and effort for their Fibre Channel networks, switching to Ethernet means a start-over with extra expenses. Thus Ethernet isn't always a price-wise option.

Besides, the maintenance fee is also a factor that should be considered. In large IT systems, if an Ethernet switch breaks down, most admins can deal with it. However, when there is something wrong with the Fibre Channel switches, they need to turn to manufacturers, instead.

Further Considerations

Many Ethernet proponents may argue that Fibre Channel is dying on account of Ethernet's high-performance, simplicity, and popularity in most applications. For new network implementations, if you've not invested in FC, Ethernet networking is considered a good way to go. However, as the only long-term de facto solution for enterprise-level data storage, insisting on Fibre Channel is more persuasive. An alternative form of Fibre Channel called Fibre Channel over Ethernet (FCoE) was invented to lower the cost of FC solutions by eliminating the need to purchase HBA (host bus adapter). Sticking to Fibre Channel, jumping ship for Ethernet, or picking FCoE solution all depend on your needs.

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