What are Fiber Channel and Fiber Channel Transceiver?

The FC (fiber channel) transceiver is an essential part of Fibre Channel infrastructures, whereas the Ethernet transceiver coupled with an Ethernet switch is a popular matching combination when deploying Ethernet networks. It is clear that the two types of transceivers serve different applications, but what exactly is the difference between them? This article will give a detailed introduction to Fibre Channel and fiber optic transceivers.

What is Fiber Channel Technology?

Fibre Channel is a fast data delivery network protocol that allows for the orderly and loss-less transfer of raw block data. Fibre Channel can connect general-purpose computers, mainframes, and supercomputers with storage devices. It is a technology that primarily enables point-to-point (two devices connected directly to each other) and is typically most common in switched fabric (devices connected by Fibre Channel switches) environments.

The SAN (storage area network) is a private network for storage connections among host servers and shared storage, it is typically a shared array that provides block-level data storage. Generally, a Fibre Channel SAN would be installed in applications with low latency where block-based storage is most appropriate, for example, databases for high-speed online transaction processing (OLTP), like those in banks, online ticketing, and virtual environments. Fibre Channel usually runs on fiber optic cables inside and between data centers, In addition, it can also be used with copper cables.

Using a Fibre Channel fabric also facilitates remote Disaster Recovery and Business Continuance, SANs are also generally designed to contain redundant structures.  Starting in 1988, Fibre Channel was first standardized by Technical Committee T11 of the International Committee for Information Technology Standards (INCITS), which is an American National Standards Institute (ANSI)-accredited standards committee. The Fibre Channel Physical and Signaling Interface (FC-PH) was released in 1994 as the first version of the fiber channel interface.

What is a Fiber Channel Transceiver?

As we mentioned above, Fibre Channel can transmit the raw block data, build a lossless transmission, Fibre Channel transceivers also use high-speed data transmission protocols, engineers generally use Fibre Channel transceivers to build transmission links between data centers, servers, and switches.

Fibre Channel transceivers also use Fibre Channel Protocol (FCP) for transmission, it is usually used for the interface of Fibre Channel systems to each other, and optical storage network devices to each other. The fiber channel transceivers are primarily designed for linking Fibre Channel storage networks within data centers. Characterized by small form factors and low cost of power consumption, the appearance of fiber optical channel modules fulfills the requirement of transmitting a huge amount of information quickly and without loss. Fibre Channel modules essentially operate at Fibre Channel rates from 1Gbps to 128Gbps, with 256Gbps and 512Gbps in the roadmap. They are available in popular form factors of SFP, SFP+, SFP28, SFP56, and QSFP28.

Figure 1: Fiber Channel Transceiver

What's the Difference between Fiber Channel Transceiver vs Ethernet Transceiver?

Protocol and Security

Fiber Channel transceivers, which are part of the Fibre Channel protocol, and it is not compliant with the OSI model layering. Instead, the Ethernet transceiver complies with the IEEE 802.3 standard, it will enable physical packet-based communication in a local area network. Fibre Channel is a data link layer protocol in the TCP/IP stack and is part of the OSI model.

Fibre Channel systems are designed for a high-security level because the storage area network (SAN) and other data layers in the system do not interact with each other, so the storage network is difficult to be attacked and data leakage is avoided as much as possible, using FC optical modules can largely increase the security of the system. Ethernet modules, on the other hand, operate under the TCP/IP protocol, which the back-end administration can access during the operation of the network, and therefore, Ethernet module systems may have some security flaws. Using an FC system will be more secure than an Ethernet system. Some Ethernet modules have FC transmission protocols such as the 10GBASE-SR module.

Figure 2: Ethernet Transceiver

Reliability

The two different transmission modes bring completely different transmission results due to the use of different protocols. Comparing the differences, Fibre Channel is much better than Ethernet transceivers in terms of reliability. Also, Fibre Channel can accomplish lossless data transfer, and with these features combined, Fibre Channel is generally deployed in storage networks. The different transmission results we mentioned earlier is that Fibre Channel is often used in SAN systems, while Ethernet is commonly used in NAS systems. In different usage areas, fiber optical channel modules can achieve high speed and low latency to meet data center needs for block storage, while when file-level storage access is to be performed, it is better to use Ethernet transceivers.

Transmission Speed

Comparing Fibre Channel transceivers and Ethernet transceivers, the range of transmission speeds is also varied. FC modules currently allow 1Gbps/2Gbps/8Gbps/16Gbps/32Gbps/128Gbps, while Ethernet modules have more diverse transmission speeds: 10/100/1000Mbps and 10Gbps/25Gbps/ 50Gbps/40Gbps/100Gbps/400Gbps.

We can find that the iteration rate of fiber optical channel modules is usually counted by 2 times, from 1Gbps to 32Gbps, while Ethernet modules have been developing faster than we can imagine in recent years, and some suppliers have started to produce 400G Ethernet modules, and the new 400G Ethernet QSFP-DD modules have grown 400 times compared to the first Gigabit SFP modules. So if the current data center needs more bandwidth, the development of Ethernet modules can better meet the increasing bandwidth demand.

Application

The applications of Fibre Channel transceivers and Ethernet transceivers are also different. Fibre Channel is commonly used to connect servers and storage devices, this link is one of the best ways to transfer large amounts of data. It should be noted that FC module can only be used with FC switch, this combination is mostly used for Fibre Channel, storage network and Ethernet applications, when it runs on Ethernet it can run directly on Ethernet in the form of FCoE, currently, FC module and FC switch have been widely deployed in data centers.

Ethernet transceivers have been used in LANs and sometimes WANs since their inception. Unlike FC modules, which have a fixed range of use, Ethernet can be deployed in small offices to very large data centers depending on bandwidth requirements.

Conclusion

This article introduces the differences between Fibre Channel transceivers by comparing them to Ethernet transceivers. Fibre Channel is used in many large enterprises and large data centers due to its specific usage scenarios, which allows it to be deployed in many large enterprises and large data centers, while Ethernet modules have the advantage that it has a wide range of applications. If you want to know more about fiber channel and fiber channel transceivers, you can contact QSFPTEK via sales@qsfptek.com.  QSFPTEK offers high-quality, cost-effective FC transceivers, and Ethernet transceivers in a variety of models.