2025

Is a 1.25g optical module a Gigabit module?

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Yes, a 1.25G optical module is a Gigabit module.

This is because "Gigabit" in Ethernet standards usually refers to an effective data transmission rate of 1Gbps (1000Mbps) while 1.25Gbps is the transmission rate of the optical module at the physical layer.

During data transmission, Ethernet frames contain additional overhead such as preamble and inter-frame gaps (used to ensure data synchronization and transmission reliability). In order for the actual effective data rate after deducting this overhead to still reach 1Gbps, the physical layer needs to design a higher transmission rate to "offset" the overhead loss - the 1.25Gbps physical rate exactly meets this requirement.

Therefore, the 1.25G optical module is specifically designed for Gigabit Ethernet (1000BASE-X), and its core function is to achieve 1Gbps effective data transmission, which is a standard Gigabit optical module.

As a core component of Gigabit Ethernet, the 1.25G optical module's application scenarios mainly revolve around the 1Gbps effective data transmission requirement and cover multiple fields including LAN, access network, and industrial communication, specifically including:

Enterprise LAN backbone connection
In enterprise and campus LANs, 1.25G optical modules are often used to connect core switches to aggregation switches, or aggregation switches to access switches, to achieve Gigabit bandwidth transmission between buildings and floors, meeting the stable transmission requirements of internal office data, video conferencing, and file sharing.

Short-distance interconnection within data centers
For connections between servers and access layer switches within data centers, or low-speed storage devices (such as NAS storage), 1.25G optical modules can provide cost-effective Gigabit links, suitable for non-core business scenarios with low bandwidth requirements (such as backup and monitoring data transmission).

Fiber access network (FTTx) end connection
In FTTB (Fiber to the Building) and FTTD (Fiber to the Desktop) access network scenarios, 1.25G optical modules are used to convert the operator's optical signals into electrical signals, supporting Gigabit broadband access in residential areas and office buildings.

Industrial Ethernet communication
In industrial automation scenarios (such as factory production lines and smart grids), 1.25G optical modules, with their stable Gigabit transmission capabilities, can connect PLCs (Programmable Logic Controllers), industrial switches, and other devices, meeting the low-latency requirements of real-time data acquisition and device control, while also adapting to the anti-interference requirements of industrial environments.

Security monitoring system
High-definition camera (such as 1080P, 4K) video stream transmission requires stable Gigabit bandwidth. 1.25G optical modules can be used to connect front-end cameras to back-end NVRs (Network Video Recorders) or monitoring switches to ensure smooth, low-latency video data transmission.

In summary, 1.25G optical modules, with their adaptability to Gigabit effective bandwidth, moderate cost, and strong compatibility, are widely used in medium and short-distance scenarios requiring stable Gigabit transmission, and are one of the mainstream choices for Gigabit network deployment.

1.25G optical module

10 Gigabit single-mode optical module

Differences in RJ45 connector models

10 Gigabit single-mode optical module

Differences in RJ45 connector models