40/100G Multi-mode Fiber Solutions for Data Center Network

Hyperscale enterprises are moving forward with deploying 200/400G/800G networks, while some other companies are still in the process of migrating to 100G networks. 40/100G cabling solutions share similarities in interface and fiber selection, but their respective deployments also depend on many factors such as data center infrastructure, cost budget, data throughput, etc. This article explores the 40/100G multi-mode fiber solution in data centers, emphasizing the reasonable layout of cabling through technical methods.

Considerations for 40/100G Network Upgrades

The rapid development of the Internet and the upgrade of 40/100G data centers have driven the changes and development of data center internal infrastructure and cabling. The diversified deployment of 40/100G multi-mode fiber cabling is a typical example. Here are a few factors driving data center upgrades.

Link Distance and Power Loss Amount

For most data centers, the wiring distance is short, the link loss of the inherent transmission distance is small, but the power loss at the connection is relatively large. And as data center connections continue to increase, so does power loss. Therefore, data center cabling must balance manageability and performance. Selecting 40/100G multi-mode fiber with low power loss or using SWDM (short-wave division multiplexing) technology can effectively ensure the operating environment of the data center cabling system.

Cabling Infrastructure Design

TIA-942, as a data center telecommunications infrastructure standard, emphasizes the cabling infrastructure landscape. Structured cabling based on 40/100G multi-mode fibers can grow or move as data center needs and throughput demands change. Implementing a structured cabling system can reduce the volume of cabling in under-floor and overhead transport, and it can also reduce airflow obstructions, thereby reducing electricity costs. Additionally, the structured cabling solution supports a modular design, which means that if there is maintenance or upgrade, it can only be done by changing connectors without removing horizontal or distribution cabling.

40/100G Multi-mode Fiber Cabling Connectivity Options

When upgrading 40/100G cabling, there are several connectivity options to consider.

The multi-mode short-distance transmission optical module mainly refers to the parallel transmission of data and aggregates multiple optical fibers for data transmission and reception. In 40/100G multi-mode fiber cabling, 40/100G SR4 optical modules can be used for data transmission. With the 802.3bm standard update, 100G SR4 allows 100G Ethernet speeds using 12-fiber fiber with MPO interfaces.

QSFP MM optical module has the MPO interface and also provides more choices. Duplex LC packaging has advantages in many aspects, such as cost, performance, etc. Both QSFP 40G and BiDi SFP transceivers can utilize LC duplex packaging to improve data transmission performance.

40/100G Multi-mode Fiber Connectivity Solutions

The data center rate is upgraded from 10G to 40/100G, and the 100-meter channel deployment of OM3/OM4 cable is more common. However, there are two specific deployment ways of deploying data centers, both of which can be implemented 40/100G multi-mode fiber data transmission within the data center.

Parallel Optics Technology in 40/100G Multi-mode Fiber Connectivity

Parallel optical technology transmits and receives data through multiple optical fibers, and has the value of reliable and low-cost cabling design. For example, 40GBASE-SR4 parallel transmission requires 4 pieces of OM3/OM4 cables at the transmitter and receiver, each with a transmission rate of 10G to complete 40G transmission.

Similarly, the transmitter and receiver of 100GBASE-SR4 also need to use 10 pieces of OM3/OM4 fibers for 100G transmission. However, with the development of VCSEL technology, the availability of the 25G modulation rate has been improved, which enables the duplex multi-mode fiber of the MPO/MTP interface to achieve the performance of using 4 fibers for transmission and reception respectively, reducing the optical link loss. The transmission distance of OM3/OM4 in 100G multi-mode fiber connection can also reach 200/300 meters, and 40G can reach 300/400 meters.

WDM Technology in 40/100G Multi-mode Fiber Connectivity

In addition to the above-mentioned parallel optical technologies, there are also BiDi optical modules or SWDM (short wavelength division multiplexing) solutions suitable for the deployment of 40/100G multi-mode fibers inside the data center. The 40G BiDi optical transceivers have two 20G optical channels for bidirectional transmission and receive through each fiber, with distances up to 100/150/200 meters on OM3/OM4/OM5.

The 100G BiDi optical module has two 50G optical channels, bidirectional transmission on each fiber, and the specified distance on OM3/OM4/OM5 can reach 70/100/150 meters. On the other hand, the design of SWDM optical modules is mainly to run through OM3/OM4 fibers in existing data centers, and it can utilize four 25G wavelength optical modules to achieve the 100G rate.

40/100G Multi-mode Fiber Recommendation

The deployment of 40/100G data center networks can use parallel optics or WDM technology, using multi-mode fiber to achieve reliable and low-cost data transmission value. Both FS multi-mode fiber and BiDi optical modules support 40/100G multi-mode fiber data center network deployment.

FS multimode fiber has less attenuation when bent or twisted than traditional fiber optic cable, enhancing cable installation and maintenance efficiency. Additionally, they also save more space for your high-density wiring. OM5 supports emerging SWDM applications, reducing the number of parallel fibers by at least 4 times to continue to use only two fibers for 40Gb/s and 100Gb/s, and reducing the number of fibers for higher speeds.