A Quick Guideline to FC Optical Transceiver

What is fiber channel technology?

Fiber Channel technology (Fibre Channel) is a network storage switching technology that can provide long-distance and high bandwidth, and can realize the transmission of large data files between storage, server and client nodes.

Fiber Channel (FC) is a high-speed network interconnection technology (usually operating at 2Gbps, 4Gbps, 8Gbps and 16Gbps), which is mainly used to connect computer storage devices. In the past, Fiber Channel was mostly used for supercomputers, but it has also become a common connection type in enterprise storage SANs. Although called Fiber Channel, its signals can also run on twisted-pair wires other than fiber optics.

Fiber Channel Optical Module Features
Fiber Channel (FC) optical modules are used for fiber channel storage network links in data centers. Including transmission, reception, clock data recovery and control and other parts. Fiber Channel optical modules can be backward compatible with Fiber Channel applications, support optical loopback and circuit loopback diagnostic tests, and provide stable receiving alarms. As the interface between fiber channel systems and optical storage network storage devices, it has the characteristics of miniaturization and low power consumption, which can increase the port application density; it supports hot plugging, which is convenient for on-site debugging of the system, and can realize optical replacement without power failure Module; support digital diagnostic interface, the network management can monitor the working status of the optical module through the communication interface.

Why do data centers use Fiber Channel optical modules for storage networks?

Availability: The data storage of the core business cannot be interrupted, and the FC network can ensure that the data can be accessed in real time.

Performance: The core business has higher and higher performance requirements, and Fiber Channel provides better performance.

Scalability: The FC network can ensure that when the business expands, the scale increases, and the storage capacity increases, there is a corresponding network foundation that can support such a business system.

Security: Fiber Channel is inherently a security system. A hacker can attack into the ID network of the data center and attack your server. Because our SAN network is naturally isolated from the outside world, it is impossible for it to attack your storage network. Through the SAN network, data can be protected and the risk of data leakage can be reduced.

What is the difference between a Fiber Channel optical module and an Ethernet optical module?

Transfer Protocol

Fiber Channel (FC) optical modules follow a different protocol than Ethernet optical modules. The FC optical module belongs to the Fiber Channel protocol and does not follow the OSI model layering, while the Ethernet optical module complies with the IEEE 802.3 standard and realizes physical communication based on data packets in the LAN. It is a data link layer protocol in the TCP/IP stack and belongs to the OSI model. FC optical modules are compatible with Ethernet protocols, while Ethernet optical modules do not support Fiber Channel protocols.

Reliability

The reliability of the FC optical module is better. Fiber Channel optical modules are designed for users who pursue high-speed, low-latency block storage. If users need file-level storage access, the Ethernet module is given priority.

Transmission Rate
FC modules currently support rates of: 1Gbps, 2Gbps, 8Gbps, 16Gbps, 32Gbps, 128Gbps, while Ethernet modules can support a wider range of transmission rates: 10/100/1000Mbps and 10Gbps, 25Gbps, 40Gbps, 50Gbps, 100Gbps, 200Gbps , 400Gbps.

In addition, the replacement rate of each generation of FC modules is usually calculated to the power of 2, from 1Gbps to 32Gbps. It is obvious that the throughput improvement of Ethernet modules far exceeds that of Fiber Channel modules, and the 400G Ethernet QSFP-DD modules are nearly 400 times that of the original 1G SFP modules. Obviously, the Ethernet optical module is more in line with the current growing demand for high bandwidth than the FC optical module.

Application Field

Traditional Fiber Channel networks, including FC switches and Fiber Cards (FC HBAs), are one of the main options for SANs. FC switches connect the storage to the SAN, while fiber cards connect the switches to the servers. Fiber Channel is one of the best ways to transfer large amounts of data between servers and storage devices. Therefore, FC modules connected to FC switches are mainly used in Fiber Channel, storage network and Ethernet applications. Fiber Channel communications can run over Ethernet via the Fiber Channel over Ethernet protocol (FCoE). Obviously, FC modules have long been used in large enterprises and data centers.

Ethernet optical modules are usually used in local area networks, and sometimes in wide area networks. Compared with the working scenarios of the FC module, the application environment of the Ethernet module is based on the user’s bandwidth requirements and is more flexible and diverse. It can be seen on various occasions, from small offices to ultra-large-scale data centers. Ethernet network switches are diverse, reflected in stackability, number of ports, transmission rate, etc.

Summary

Compared with high-IO and high-performance requirements of high-end all-flash arrays, Gen 6 32 Gbps Fiber Channel is especially important for new technologies such as flash memory that are driving the rapid transformation of data centers. As enterprises leverage flash memory to redesign their data centers and optimize application performance, they need networks that deliver low latency, high capacity bandwidth and reliability. Currently, 70-80% of flash array storage systems have been deployed using Fiber Channel. In the future, next-generation flash memory based on the Non-Volatile Memory Standard (NVMe) will seamlessly integrate with Gen 6 Fiber Channel networks.