400G in Data Centers: What You Need to Know – SAPPLY

The next generation of cloud infrastructure is here!

Welcome, 400G.

400G is a four times increase in data-transfer speed. It also has more lanes, which allows for more data processing at a time. Data centre operators are quickly phasing out lower-speed transceivers of 10G or below. And, there is a buildup of mega data centres using 100G and 400G technology.

Keep reading to learn more about 400G optical transceivers and their uses.

400G Optical Transceivers

400G optical transceiver is a single, packaged device. It works as both a transmitter and receiver. This transceiver converts electrical signals to optical signals and vice versa. Optical networking for broadband widely uses optical transceivers.

Manufacturers test transceivers for transmitter optical power and receiver sensitivity to meet defined specifications for users.

The Need For More Speed

There is a growing need for massive data centres. Increasing demands for bandwidth, capacity and lower latency test cloud-scale data centres every year. Link speeds have exploded. They moved from 10G to 25G, then progressed even faster to 100G and now 400G.

As data centres move toward faster and more scalable infrastructure, they rely on high-capacity connectivity. The connectivity stabilizes the expanding number of users, devices and applications. Higher speeds are the inevitable evolution of data centre services.

The need for higher speeds comes from wide-area-network telecommunications applications, enterprise augmented reality and the Internet of Things (IoT). There are already billions of IoT devices connected to the Internet.

Specific items that contribute to exponential traffic growth are:

  • Open systems
  • Artificial intelligence (AI)
  • Machine learning
  • Cloud storage

Additionally, with the rise of 5G mobile data, 400G transceivers are necessary to move information through data points.

While many data centres still use between 10G and 100G technology, 400G transceivers are rapidly becoming the new standard. By 2023, experts say the global 400G optical transceiver market will be more than $22bn. In addition, this next generation of devices use less power, are less expensive, are smaller, and are more intelligent.

400G vs. 400GbE vs. 400Gb/s

400G typically refers to the solution of 400G capacity on one 400G wavelength. Depending on the context, it’s interchangeable with 400GbE and 400Gb/s.

400GbE is the next capacity rate in Ethernet interfaces that can travel through a single link. The IEEE 802.3bs standard lays out the parameters 400GbE must meet. This includes physical layers, management parameters, and Media Access Control (MAC).

Finally, 400Gb/s is the data transfer speed. This means 400 billion bits of information can travel through one optical wavelength every second.

AOCs and DACs

An Active Optical Cable (AOC) is a technology that accepts the same electrical input as a standard copper cable. However, it uses optical fibre between the connectors. The electrical-to-optical conversation on the ends improves speed and distance performance.

It does this without losing compatibility with standard electrical interfaces. The idea behind AOCs was to replace copper technology in data centres and high-performance computing (HPC) applications. AOCs have high transmission rates, long transmission distances, low energy consumption, and are convenient.

On the other hand, a Direct Attach Cable (DAC) is a fixed-length cable with fixed connections at both ends. The connector at each end is the same as the interface of the optical transceivers. But, the connector module does not have expensive optical lasers or other electrical components.

This massively reduces costs. It also makes for highly efficient and fast data communication. DACs are popular with storage area networks, data centres, and HPC connections. This is because they connect switches to routers or servers.

Even though AOCs have many advantages, DACs are still quite popular. DACs have a shorter transmission distance than AOCs. Thus, they are better for short-distance cabling in data centres.

Plus, DACs have a copper core. Copper is a natural radiator, so it had good heat dissipation. This saves more energy, making it environmentally friendly. As a result, DACs have a lower-power consumption than AOCs.

Network Backhaul

Additionally, AOCs and DACs assist with network backhaul. Backhaul is the connection between an access node and the core network. To plan a network backhaul consider these factors:

  • Bandwidth (required transfer rate)
  • Latency (the time it takes for data to go from one place to another)

There are two common types of backhaul infrastructures. They are fixed-line or wireless. Users need to build their own fibre infrastructure for fixed-line network backhaul or lease unused (dark) fibre. With dark fibre, the infrastructure comes from a third party that owns the setup. Laying new fibre-optic cable lines is costly and slow.

Of course, wireless network backhaul systems don’t require the use of AOCs and DACs. Yet, wireless networks cannot process as much information at the speed at which fixed-line networks can.

New Fibre Packaging

The rise in speed means revolutionising fibre cabling. Higher bandwidth and capacity demands push for higher fibre counts. In the past, data centres used no more than 96 strands. This included coverage for diverse and redundant routing.

But today, fibre counts of 144, 288, and 864 are typical.

The high fibre count takes up crucial space in raceways. Large cable diameter brings performance challenges. So, cable OEMs are moving toward using rollable-ribbon construction and 200-micron fibre.

Standard ribbon fibre bonds have 12 strands along the length of the cable. But, rollable ribbon fibre is intermittently bonded. As a result, the fibre is rolled and doesn’t lay flat. The rollable-ribbon design allows 3,456 strands to fit into a two-inch (about five-centimetre) duct.

The flat design can only allow 1,728 strands to fit in the same two-inch (five-centimetre) space.

Even further, some manufactures offer 6,912- and 7,776- strand fibre cables.

Upgrade to 400G

Global adoption of the Internet is driving the need for massive data centres. Thus, 400G optical transceivers are necessary for communications, servers, and other electronic systems. Anything below 400G will soon be obsolete.

To browse 400G solutions, contact us at Sapply. Our technical experts provide local market knowledge to help vendors tap into new opportunities.