FAQs about 100G Ethernet Transmission

With the development of fiber technology, the 10G/40G Ethernet transmission can no longer meet the needs of enterprises for larger capacity and higher speed data transmission. As 100G Ethernet matures, more and more users choose to deploy 100G Ethernet networks for data center interconnect (DCI) and 100G DWDM networks at a reasonable price. Below are some frequently asked questions related to 100G Ethernet.

Q: What Is 100G Ethernet?

A: 100G Ethernet refers to a version of computer networking technologies that supports the transmission of data at a rate of 100 gigabits/s. It can offer higher achievable data transmission speed while maintaining integration with existing Ethernet technologies and interfaces.

Compared with other 10G/25G/40G Ethernet technologies, 100G Ethernet shows its advantages in several ways. Firstly, 100G Ethernet guarantees faster data transfer speed, faster access to files in corporate networks, and can solve complex requests in data centers. Secondly, the 100G Ethernet products, like transceivers or other network devices, are back-compatible and the cabling system installed for lower speed can be reused, thus simplifying cable management and reducing power requirements and cost. Thirdly, 100G Ethernet also allows enterprises to adopt new technologies, such as Remote Direct Memory Access, RDMA over Converged Ethernet, etc.

Q: What Is the Standard of 100G Ethernet?

A: 100G Ethernet was originally defined by the IEEE 802.3ba standard in 2010, and later by the IEEE 802.3bg standard in 2011, 802.3bj standard in 2014, 802.3bm standard in 2015, and 802.3cd standard in 2018.

Q: What Is the Application of 100G Ethernet?

A: Generally speaking, 100G Ethernet is an ideal solution for long-haul and switch-to-switch transmission. What's more, it is also suitable for data centers and large enterprises that require high-bandwidth and low-latency transmission, especially for those with large virtualized and pooled virtual machines and containers.

In addition, 100G Ethernet can also be applied in these scenarios:

• Switching, routing, and aggregation in data centers;

• Network exchange points;

• Service provider peering points;

• High-bandwidth applications;

• High-performance computing or cloud infrastructure.

Q: What Parameters Will Influence 100G Transmission Performance?

A: In the process of the implementation of 100G Ethernet network, it may be influenced by several factors, such as the bandwidth, insertion loss, and so on.

• Skew: The first parameter that impacts 100G Ethernet transmission is skew. To be clear, skew means the time-of-flight difference between optical signals traveling on different fibers. As an inherent part of 100G Ethernet, skew is closely related to 100G Ethernet that uses parallel optics. In the parallel optic system, one data stream can be split into multiple data streams and transmitted over different fibers, allowing the use of lower-cost transceivers.

• Bandwidth: Bandwidth is another important factor that restraints 100G Ethernet. With enough bandwidth, the 100G Ethernet can achieve the transmission distance of at least 100m over OM3 and OM4 fibers, thus better meeting the requirements of businesses.

• Insertion loss: Most of the time, insertion loss refers to total optical power loss caused by an inserted component, such as a connector or coupler. It may be caused by air gaps between matching ferrules or loss of absorption due to scratches and contamination. The 100G Ethernet performance can be improved greatly with reduced insertion loss.

Q: What are the distances and insertion loss budgets for 100G?

A: 100G Ethernet supports up to 100m link lengths over the and 150m over OM4 MMF and the OM5 MMF. OM3, OM4, and OM5 are common multimode fibers that comply with the 100G standard. The channel loss budget for OM3 is 1.9dB, including 1.5dB of total connector loss. As for OM4 and OM5, the channel loss budget is 1.5dB, which includes a total connector loss of 1.0dB.

Q: What transmission method will be used for 100G?

A: 100G Ethernet over OM3, OM4, and OM5 multimode fibers is based on parallel optical transmission. In contrast to traditional serial transmission, parallel optical transmission uses a parallel optical interface. Therefore, data can be transmitted and received at the same time through multiple fibers. The 100G interface usually uses 10x10G Ethernet channels on 10 fibers in each direction. In addition, 100G Ethernet can also be reached over MTP or LC single-mode fibers, which can be better used for high-density data center applications.