How to increase the efficiency of data center connections?

20/7/2022
Traditionally, data centers have been seen as institutions that did not offer companies much flexibility. If the company wanted to expand its data capabilities, it had to invest in the purchase of more server space.
However, this did not solve the security problems, since all the data was stored in only one place. With the rapid advancement of telecommunications, it is possible to connect remote data centers in a versatile and economical way using DWDM systems.

Despite the impact of COVID-19, European data centers attracted in the first half of 2020 investments worth approximately £23.5 billion - according to The Knight Frank Data Centre Report. For comparison, in 2019, the volume of investments was only $2 billion. The growth is impressive, and companies such as Amazon, Facebook and Google have not yet said the last word.

As the size and number of companies choosing to store their information in data centers increases, the demand for more bandwidth increases. Data centers can simultaneously store data from giant corporations like Google and data from smaller companies. This means that they must meet the needs of a customer who needs 1GbE or 10GbE connectivity, and an international corporation that requires 100GbE or even 400GbE.

Placing Data Center branches in different locations minimizes the risk of external threats to customer networks and increases backup capabilities. In addition, handling sensitive data requires the use of strong encryption protocols with strict accessibility policies.

Bandwidth, distance and security — xWDM (Wavelength Division Multiplexing) systems are the answer to all of these challenges for data center operators. They allow multiple transmissions to be duplicated and transmitted using a single fiber infrastructure, which consequently allows for more efficient use of the medium and to meet the needs of small and large customers.

CWDM or DWDM?

The traditional solution used by data centers is Coarse-Wavelength Division Multiplexing (CWDM), that is, a convenient and cheap technology that allows you to connect up to 18 channels on a single pair of fibers. This allows efficient operation at a distance of up to 40 kilometers.

However, CWDM has its limitations. Increasing the distance to 80 kilometers between Data Center branches, we must take into account the fact that only 8 channels will function properly. The channels are transmitted simultaneously through a single optical fiber, with the distance between the central wavelength of each channel being 20 nanometers. Because of this, the CWDM system cannot be amplified. The small number of channels also limits the data rate to about 10 Gigabit Ethernet and 16Gb Fibre Channel.

Unlike CWDM, in DWDM systems we can use optical amplifiers, which is why they are used to transmit data over much greater distances, even several thousand kilometers. DWDM is capable of operating at 40 to 160 separate wavelengths.

To support 48 channels for a 100 GHz network, a gap of 0.8 nanometers must be maintained, while the gap to obtain 96 channels for a 50 GHz network is 0.4 nanometers. This means that huge amounts of data can be transmitted over a single fiber, with each channel having a speed of 400 Gbps and 64 channels per pair of fibers.

Another advantage of DWDM is that networks are transmitted at distinct wavelengths, and the channels do not interfere with each other, which means that they can use different data formats and be transmitted at different speeds. This feature is essential to maintain data integrity and ensure any security-related divisions when multiple tenants are located in the same data center.

All in all, DWDM technology is a better solution for high-bandwidth data transmission and long-distance connectivity. It can also be used in densely distributed data centers, especially hyperscale cloud service providers or colocation service providers.

Data Center Interconnect (DCI)

Data Center Interconnect (DCI) is a technology that connects data centers over short, medium and long distances using high bandwidth connections.

To achieve an effective DCI strategy, companies may choose to use muxponders. For example, PacketLight's PL-4000M muxponder provides 400G bandwidth on a single wavelength in a 1U chassis. Works with 400G CFP2-DCO coherent modules for metropolitan and long-distance applications. On the client side, it supports 25/100/400Gb Ethernet as well as 16/32G Fibre Channel. Transmission security is ensured by optical layer one encryption (GCM-AES-256) using Diffie-Hellman key exchange.

However, for large corporations that require connectivity over even greater distances, a more appropriate option is to use QSFP+/QSFP28 ports. By installing a transport solution directly into such devices, users can eliminate additional equipment and significantly reduce network deployment and maintenance costs.

Solution QSFP28 DWDM Based on advanced pulse-amplitude modulation, it provides up to 4 Tbps of bandwidth on a single fiber and facilitates the connection of data centers up to 120 km away. The big advantage of this solution is the fact that the modules are installed directly in the network devices, and their signal goes immediately to the multiplexers. Thanks to this approach, companies can have an economical and at the same time scalable solution.

To run QSFP28 DWDM, you will need the right multiplexers, optical amplifiers, and chromatic dispersion compensators. This is a one-time investment. A recent analysis by ACG Research found that the use of QSFP28 DWDM optical modules installed directly into network devices saves users between 58 and 67 percent on the total cost of ownership (TCO) of optical modules, compared to transmission between data centers up to 80 km away. This provides companies with a quick return on investment while giving them the ability to scale.

For example, to run another 39 100Gbps transmission channels, data center managers only need to use the appropriate optical modules.

Porta QSFP+/QSFP28 not only reduces costs, since it takes up a minimum amount of space in the rack, but also reduces the power consumption per transmitted bit. This makes it ideal for connecting data centers over long distances.

Modern data centers require modern and advanced solutions. They are no longer seen only as data storage spaces, but increasingly as a viable solution to scale enterprises and improve customer satisfaction by offering them secure and easy access to their data. Higher speeds, more channel capacity and longer distances make DWDM the ideal technology for connecting data centers.

Want to learn more about the DWDM solutions offered by Salumanus? Write to us: sales@salumanus.com