CFP vs. CXP 100G Transceiver Modules, What's the Difference?

Author Yana

Date 12/20/2024

This article explores the key differences between 100G CFP and CXP form factor optical transceivers, revealing which is best for your network's performance needs.

100G CFP transceiver and CXP transceiver modules support hot-pluggable and support the same rate. The two 100G optical modules look similar, but in fact, there are some differences. This article will help you understand the differences between CFP vs. CXP and help you better distinguish and use them.

100G CFP Optical Transceiver Introduction

What is CFP Form Factor Defined by the CFP-MSA Committee?

CFP, short for C form-factor pluggable, is an optical device that transmits high-rate data signals. It can usually transmit rates of 40G, 100G, or even 400G. This form factor meets the CFP MSA protocol standard, which defines the hardware interface specifications and management interface specifications of CFP optical transceivers at different rates.

As needs continue to change, the CFP form factor has undergone several iterative upgrades, resulting in smaller and more efficient form factors such as CFP2 and CFP4, which provide higher transmission rates and lower power consumption. Therefore, although CFP is still used within a specific range, in modern applications, CFP2 and CFP4 are gradually becoming mainstream.

CFP(including CFP/CFP2/CFP4) and QSFP28 are common form factors for 100G transceivers, and if you want to learn more about their differences, we recommend reading this article: CFP vs. QSFP28 100G, What's the Difference?

What is the CFP Optical Module?

The 100G CFP optical module adopts a pluggable design, has a large size, supports transmission on single-mode and multi-mode optical fibers, can carry higher bandwidth and more signal channels, and is usually used for long-distance transmission. It supports different transmission protocols and interface standards, can provide high-performance, low-latency optical fiber communication solutions, and is widely used in scenarios such as data center interconnection and backbone network construction.

100G CXP Optical Transceiver Introduction

What Does CXP Mean?

CXP optical module is another high-speed optical module in the 100G optical module market. The "C" represents 12 in hexadecimal, the Roman numeral "X" represents a 10Gbps transfer rate per channel, and the "P" refers to a hot-swappable pluggable. Due to the wide application of QSFP28 optical modules, the reputation of CXP optical modules is not so prominent in comparison.

The CXP optical transceiver is 45mm long and 27mm wide. It is slightly larger than the QSFP28 optical module and smaller than the CFP2 optical module. There are 12 built-in transmission channels, each channel operates at a speed of 10Gb/s, and the maximum rate can reach 120G. It is mainly used to meet the high-density needs of data centers. It is usually used with multi-mode optical fiber. When paired with OM3 optical fiber cables, the transmission distance is 100M. When paired with OM4 optical fiber cables, the transmission distance is 150M.

CXP optical transceivers mainly target the high-speed computer market and complement CFP optical modules in Ethernet data centers.

100G CXP Optical Transceiver

How Does 100G CXP Optical Module Work?

The 100G CXP transceiver utilizes 850nm VCSEL (Vertical Cavity Surface Emitting Laser) technology, PIN array technology, and integrated laser driver chips. The combination of these technologies provides excellent optical performance at high speeds. The 100G CXP optical transceiver is designed for 850nm multimode fiber systems, with an electrical interface that uses an 84-contact edge connector and an optical interface that uses a 24-fiber MPO/MTP connector. During operation, 12x 10G electrical signals are converted into 12x 10G optical signals and transmitted via 24-fiber MTP/MPO multimode fiber cables.

How Does 100G CXP Optical Module Work

Usage Guidelines for CXP Modules

When using CXP optical transceivers, here are some important considerations that can help ensure their performance and longevity:

Ensure Compatibility

Equipment compatibility: Before installing the transceiver, ensure it is compatible with network equipment (such as switches, routers, servers, etc.).

Choose the Right Fiber

The CXP transceiver is suitable for 850nm wavelength multi-mode fiber (such as OM3 or OM4). To obtain the best signal transmission quality, it is better to choose a high-quality optical fiber that meets standards and ensures that the transmission distance of the optical fiber matches the module's specifications. The quality and type of optical fiber directly affect the transmission rate and stability, so the appropriate fiber type should be selected according to the application scenario.

Pay Attention to Plugging and Unplugging Operations

When plugging and unplugging CXP modules, operate carefully and avoid frequent plugging and unplugging, as this may damage the optical module's pins. In addition, try to avoid contamination of the optical module and interface surfaces and keep them clean to ensure stable signal transmission.

What's the Difference Between CXP and CFP Fiber Optic Modules?

The following table details the differences between CFP vs. CXP transceivers:

Feature	CXP Fiber Optic Module	CFP Fiber Optic Module
Size	Smaller (45mm in length, 27mm in width)	Larger (144.8mm in length, 82mm in width)
Fiber Type	Primarily supports multi-mode fiber	Supports both single-mode and multi-mode fiber
Applicable Distance	Suitable for short-range applications	Suitable for long-range applications
Applications	Primarily targeted at the cluster and high-speed computing markets	Mainly applied in metro networks and long-distance WDM transmission
Power Consumption	Lower power consumption	Higher power consumption

Conclusion

This article compares the similarities and differences between 100G CFP optical transceivers and CXP optical transceivers, mainly focusing on their form factors, transmission rate, and application scenarios. CFP optical modules are mainly used for long-distance transmission and can be used with single-mode and multi-mode optical fibers. In contrast, CXP optical modules are mainly used for short-distance high-density applications and are usually used with multi-mode optical fibers. Although the two compete in some applications, they are generally complementary, and the choice depends on the transmission distance and network requirements.