Category Archives: Direct Attach Cables

Accelerating Data Centers: FS Unveils Next-Gen 400G Solutions

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As large-scale data centers transition to faster and more scalable infrastructures and with the rapid adoption of hyperscale cloud infrastructures and services, existing 100G networks fall short in meeting current demands. As the next-generation mainstream port technology, 400G significantly increases network bandwidth, enhances link utilization, and assists operators, OTT providers, and other clients in effectively managing unprecedented data traffic growth.

To meet the demand for higher data rates, FS has been actively developing a series of 400G products, including 400G switches, optical modules, cables, and network adapters.

FS 400G Switches

The emergence of 400G data center switches has facilitated the transition from 100G to 400G in data centers, providing flexibility for building large-scale leaf and spine designs while reducing the total number of network devices. This reduction can save costs and decrease power consumption. Whether it’s the powerful N9510-64D or the versatile N9550 series, FS 400G data center switches can deliver the performance and flexibility required for today’s data-intensive applications.

Of particular note is that, as open network switches, the N8550 and N9550 series switches can enhance flexibility by freely choosing preferred operating systems. They are designed to meet customer requirements by providing comprehensive support for L3 features, SONiC and Broadcom chips, and data center functionalities. Additionally, FS offers PicOS-based open network switch operating system solutions, which provide a more flexible, programmable, and scalable network operating system (NOS) at a lower total cost of ownership (TCO).

FS 400G Transceivers

FS offers two different types of packaging for its 400G transceivers: QSFP-DD and OSFP, developed to support 400G with performance as their hallmark. Additionally, FS provides CFP2 DCO transceivers for coherent transmission at various rates (100G/200G/400G) in DWDM applications. Moreover, FS has developed InfiniBand cables and transceivers to enhance the performance of HPC networks, meeting the requirements for high bandwidth, low latency, and highly reliable connections.

FS conducts rigorous testing on its 400G optical modules using advanced analytical equipment, including TX/RX testing, temperature measurement, rate testing, and spectrometer evaluation tests, to ensure the performance and compatibility of the optical modules.

FS 400G Cables

When planning 400G Ethernet cabling or connection schemes, it’s essential to choose devices with low insertion loss and good return loss to meet the performance requirements of high-density data center links. FS offers various wiring options, including DAC/AOC cables and breakout cables. FS DAC/AOC breakout cables provide three connection types to meet high-density requirements for standard and combination connector configurations: 4x100G, 2x200G, and 8x50G. Their low insertion loss and ultra-low crosstalk effectively enhance transmission performance, while their high bend flexibility offers cost-effective solutions for short links.

FS 400G Network Adapters

FS 400G network adapters utilize the industry-leading ConnectX-7 series cards. The ConnectX-7 VPI card offers a 400Gb/s port for InfiniBand, ultra-low latency, and delivers between 330 to 3.7 billion messages per second, enabling top performance and flexibility to meet the growing demands of data center applications. In addition to all existing innovative features from previous versions, the ConnectX-7 card also provides numerous enhanced functionalities to further boost performance and scalability.

FS 400G Networking Soluitons

To maximize the utilization of the 400G product series, FS offers comprehensive 400G network solutions, such as solutions tailored for upgrading from 100G to high-density 400G data centers. These solutions provide diverse and adaptable networking options customized for cloud data centers and AI applications. They are designed to tackle the continuous increase in data center traffic and the growing need for high-bandwidth solutions in extensive 400G data center networks.

For more information about FS 400G products, please read FS 400G Product Family Introduction.

How FS Can Help

Register for an FS account now, choose from our range of 400G products and solutions tailored to your needs, and effortlessly upgrade your network.

Advantages and Disadvantages of Direct Attach Cable (DAC Cable)

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Driven by need for high speed Ethernet and increasing services like Cloud and virtual data center, many data centers have been loaded with numerous cables and various equipment. Due to this case, shortage of data center space is common but it’s getting difficult and expensive to build new or expand existing locations. Today this post intends to introduce a type of cable – DAC cable (direct attach cable), which can solve this problem effectively.

Overview of Direct Attach Cable (DAC Cable)

Direct attach cable is a type of copper cable similar to coaxial cable, but it has SFP+, QSFP+ or QSFP28 plus at each end integrated. DAC cable is usually used in data centers for short transmission between racks. Generally, according to the construction differences, the DAC cable comes in two types: passive and active DAC. Passive cable is suitable for short distances up to 10 m and active DAC has a little longer transmission distance up to 15m at 10Gbps or 40Gbps, because it has an active component to boost/receive signal. And passive DAC cable requires no power for internal electronics, which avoid consuming power or produce heat. While active DAC comes in reverse, it needs power to make its internal circuits work properly.

On today’s markets, in order to satisfy the ever growing need for cost-effective delivery of more bandwidth, there are mainly three kinds of DAC according to the transmission rate: 10G SFP+ DAC, 40G QSFP+ DAC and 100G QSFP28 DAC.

10G SFP+ cable offers the high density, low cost and low power solutions for today’s 10G Gigabit Ethernet connections. With its SFP+ interface, this twinax cable allows interconnects with hot-pluggable optical transceivers and Ethernet switches in data centers. As shown in the picture below, two Cisco catalyst switches are connected with a 10G SFP+ DAC.

two Cisco Catalyst 4948E-F Switches directly with 10G sfp+ Direct Attach Cable

40G QSFP+ cable offers a way for 40G Gigabit short distance connections between QSFP ports switches. As its name shows, 40G QSFP+ DAC has QSFP+ connectors on both ends. And it uses integrated duplex serial data links for bidirectional communication. 40G QSFP+ DAC is a little different from 10G DAC cable. There are two types of 40G QSFP breakout DAC cables: 40G QSFP+ to 4XSFP+ DAC and 40G QSFP+ to 4xXFP DAC. These breakout DAC cables can be used to migrate from 10G to 40G.

two Cisco switches connected by 40 QSFP+ to QSFP+ DAC cable

The last one is 100G QSFP28 DAC. The 100G QSFP28 DAC cables are high speed cable to meet and exceed 100G Gigabit Ethernet, providing connectivity between devices using QSFP28 ports. The 100G QSFP28 DAC includes QSFP28 to QSFP28 and QSFP28 to 4xSFP28 breakout DAC. These interconnect cables provide four channels of high speed differential signals with data rates ranging from 25Gbps up to potentially 40Gbps.

Advantages and Disadvantages of Direct Attach Cable (DAC Cable)

Twinax DAC cables come into play in data centers mainly because of two factors which also show its superiority. We all know that denser equipment in the data center or server rooms will consume more electrical power and produce more heat. That means more cooling systems are required. However, DAC cables have the potential to reduce the overall power consumption and heat dissipation, which help network operators save cost. Another factor is that DAC cable is robust and does not need patch panels or additional cables when connected to devices, as is the case with an optical module. The modules on both ends make them sturdy and reliable as well as space-saving.

40gbase-qsfp+-to-4-sfp+-breakout-dac

Nothing can be perfect, so do the DAC cables. Although they can save space and cost for data center managers, the drawbacks still exist. As the main element of DAC cable is copper, it is heavy and bulky, causing difficulties for management. What’s more, if DAC cables are deployed in high volume, the cable diameter and cable stiffness are another problem that should be considered. In this case, active optical cables (AOC cables) seem to be a better choice, for they are made of thinner and more pliable optical cable.

Summary

DAC cable provides a low power consumption and high-speed solution for data center interconnections. With the ability to support data rate of 10G, 40G and 100G, they are now widely used in optical links. All the DAC cables mentioned above are supplied in FS.COM. If you need to know more details, please visit www.fs.com or directly contact us via sales@fs.com.

Related Article: Use High Speed Direct Attach Cable for Data Center Interconnection

                         SFP+ DAC Twinax Cable Deployment Considerations 

Two Main Questions About Direct Attach Cables

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The increasing bandwidth demands in data centers call for new cost-effective network solutions that are able to provide great bandwidth and improved power efficiency. As such, direct attach cables (DACs) are designed to replace expensive fiber optic cables in some Ethernet applications, like choosing SFP+ DACs and QSFP+ DACs accordingly as 10 Gigabit Ethernet (GbE) and 40GbE cabling solutions to achieve high performance. How much do you know about this kind of cable? Do you know its such basic information as classifications? If not, then you can follow this article to understand DAC in depth based on the two main questions.

Question 1: What Is DAC?

DAC, a kind of optical transceiver assembly, is a form of high speed cable with “transceivers” on either end used to connect switches to routers or servers. Often referred to as twin-ax, this direct attach twin-axial cable is very similar to coaxial cable, except for one additional copper conductor core. DACs are much cheaper than the regular optics, since the “transceivers” on both ends of DACs are not real optics and their components are without optical lasers. In some 10GbE and 40GbE infrastructures, DACs have been selected to replace fiber optic patch cord when the required link length is relatively short. And in storage area network, data center, and high-performance computing connectivity, DACs are preferable choice because of their low cost, low power consumption and high performances.

Question 2: How DAC Is Classified?

When it comes to DAC’s classifications, there exist two primary standards: Ethernet transmission rate, material of cables.

Based on Ethernet transmission rate and construction standard, 10G SFP+ DACs, 40G QSFP+ DACs, and 120G CXP+ DACs are all available, meaning that DAC can be used as transmission medium for 10GbE, 40GbE, and 120GbE applications when combined as transceivers. Typical DAC assemblies have one connector on each end of the cable. Take SFP-10G-AOC1M for example, this Cisco compatible SFP+ to SFP+ Direct-Attach Active Optical Cable assembly has one SFP+ connector on each end of the cable, designed for relatively short reach that is 1m.

SFP-10G-AOC1M, one SFP+ connector at each end

According to material of cables used, DACs are available in direct attach copper cables and active optical cables (AOCs).

Direct Attach Copper Cable

Direct attach copper cables are designed in either active or passive versions, providing flexibility with a choice of 1-, 3-, 5-, 7-, and 10-meter lengths. The former provides signal processing electronics to avoid signal issue, thus to improve signal quality. What’s more, the former can transmit data over a longer distance than the latter which offers a direct electrical connection between corresponding cable ends. Both direct attach passive copper cables and direct attach active copper cables have gained popularity in data centers. For instance, EX-QSFP-40GE-DAC-50CM, the Juniper 40G cabling product, hot-removable and hot-insertable, is the QSFP+ to  QSFP+ direct attach passive copper cable assembly, really suitable for short distances of up to 0.5m(1.6ft), appropriate for highly cost-effective networking connectivity within a rack and between adjacent racks.

EX-QSFP-40GE-DAC-50CM, for short reach

Active Optical Cable

AOC is also one form of DAC. It uses electrical-to-optical conversion on the cable ends to improve speed and distance performance of the cable while mating with electrical interface standard. Compared with direct attach copper cable, its smaller size, electromagnetic interference immunity, lower interconnection loss and longer transmission distance make it popular among consumers.

DACs offer great flexibility in cabling length choices, simplify server connectivity in top-of-rack deployments, and reduce the power needed to transmit data. More importantly, DACs ensure high system reliability after going through rigorous qualification and certification testing, helping network designers to achieve new levels of infrastructure consolidation while expanding application and service capabilities.

Conclusion

DACs are able to provide an end-to-end solution that is easy to maintain, thus helping improve the availability of networks that support mission-critical applications. Fiberstore offers a broad selection of DACs with high quality for state-of art performance, 10G SFP+ DACs, 40G QSFP+ DACs, and 120G CXP+ DACs all included. For more information about DACs, you can visit Fiberstore.