What is DAC direct attach cable?

DAC cable is a short-distance, low-cost line connection solution as stacking cable, it is widely used to achieve stacking between devices in a group of cabinets.

DAC cable are the same as AOC active optical cables. Both ends of the high-speed sfp cable are optical transceivers, which are connected by copper twinax cable in the middle. The optical modules are coupled and fixed with the cables and cannot be separated. Compared with AOC cable, the modules at both ends of the sfp to sfp cable don’t have component like optical lasers, so the cost is much cheaper than AOC cable. The transmission distance of DAC active optical cable ranges from 1M to 15M, which greatly saves costs in short distance applications.

DAC cable can be divided into 10G DAC, 25G DAC, 40G DAC, 100G DAC, 200G DAC, 400G DAC or 800G DAC according to the transmission rate. In recent years, the emergence of active DAC has provided a guarantee for reducing signal interference for longer distance transmission, and has gradually been widely used.

Cable Direct Attach Working Principle

The working principle of optical dac cable is similar to AOC cable, both of which play the role of transmitting signals. However, there are no chips on the circuit boards at both ends of DAC sfp, and the signals transmitted in the middle are all electrical signals, which do not involve the conversion from electricity to light or light to electricity. Therefore, the transmission distance of DAC cable is shorter than that of AOC cable.

SFP Direct Attach Cable International Standards

• Compatible to SFP28 MSA
• Compatible to SFF-8402 and SFF-8432
• Compliant with SFF- 8436
• Compatible with IEEE 802.3bj and IEEE 802.3cd
• Compliant with SFF- 8436, SFF-8431, SFF-8432 and SFF-8472
• Compatible with IEEE 802.3bj and InfiniBand EDR
• Compatible with IEEE 802.3bj,IEEE 802.3by and InfiniBand EDR
• RoHS Compatible

DAC Direct Attach Cable Application

DAC cable can be used in SATA storage devices, ultra-high bandwidth switches and routers, short-distance wiring between infrastructure network devices, core routers, 10G,25G, 40G, 100G, 200G, 400G, 800G Ethernet and other data center interconnection scenarios. They are widely used in data transmission between the same cabinet or adjacent cabinets in the data center.

What is the difference between DAC cable and AOC cable? ‌

DAC cable and AOC cable are both high-speed cables, used for stacking or interconnecting devices. Generally, DAC passive cables are used for stacking devices over short distances. For connections between long distance devices, generally use AOC active optical cables, which have longer transmission distances and more stable performance.

First, direct attach cable are directly connected copper wire (such as DAC passive cables), and their transmission distance is relatively short, while active optical cables have active components such as optoelectronic conversion modules inside, which enables them to support longer transmission distances, up to 100M or even farther.

Second, in terms of power consumption, copper dac cable have very low power consumption due to the absence of active components, while AOC active fiber cable have certain power consumption due to the presence of active modules. Furthermore, from a cost perspective, DAC cables are usually relatively low in cost, while aoc fiber cable are more expensive due to factors such as technical complexity.

What kind of cable is a DAC cable? What is the difference, DAC cable vs network cable?

The cable of a DAC is generally a special copper cable, which is different from a network cable. A network cable is mainly a copper twisted pair cable, which transmits data through electrical signals. Its transmission distance is relatively short, generally within 100 meters, and it is easily affected by electromagnetic interference. The cable in a DAC high-speed cable is a cable that achieves high-speed and high-bandwidth transmission. It has the advantages of fast transmission speed, large bandwidth, and strong anti-electromagnetic interference ability. This cable is made into a DAC high-speed cable. Generally, the longest transmission distance can reach 7 meters.

Frequently Asked Questions

OSFP-400G-DAC SFP Cable | New Product Realse

400G DAC cable is hot pluggable QSFP optical transceivers at both sides and ultra-convenient, compatible with multiple devices, with a transmission rate of 400gbps Ethernet, ultra-fast network application. Yingd have more than 20 sets of brand switches for comptability test.

Why is DAC copper cable 24AWG thicker and 30AWG thinner?

AWG is the English abbreviation of American wire gauge in the American telecommunications standard. xxAWG indicates the number of holes that the copper wire must pass through to form the final diameter. The larger the value, the more holes the wire passes through, and the smaller the diameter of the wire.

For example:

30awg has more holes than 24awg wire, so the diameter is smaller. The diameter of 30awg is 4mm, and the diameter of 24awg is 6mm.

For dac coaxial cable, the thicker the copper wire, the longer the transmission distance.

What is the difference between a switch and a router?

A router can assign an IP address to many hosts, which provide firewall services. A switch is only used to distribute network data.

800G OSFP-2X400G DAC Cable | New Product Release

Designed for high speed interconnection in data centers; supports PAM4 modulation technology to ensure stable and efficient data transmission; low power consumption design to effectively reduce operating costs; low latency design to meet real-time data processing needs; compatible with mainstream network equipment, it is an ideal choice for data center upgrades.

What is the difference between the IB protocol of Mellanox switch’s infiniband and the Ethernet protocol?

Both are different from 3 aspects: Bandwidth, latency and networking mode.

• Infiniband- IB protocol: the connection of high-end computing devices requires high-performance computing, high-speed interconnection between servers, and high bandwidth requirements. The latency is required to be controlled below 100ns.
• Ethernet Ethernet protocol: compatible with typical networks, just ensure normal communication requirements. The latency is generally above 200ns.

How to ensure the compatibility of 400G-OSFP-DAC?

With more than ten years of production experience, new equipment or brands have corresponding test equipment for docking and testing.

For example, 400G cables use CX6 and CX7 network cards, and 800G 9790 switches are basically compatible. Currently, only CX6 and CX7 are used to adapt to other brands on the market.

What is the service life of 400G OSFP DAC cable?

DAC cable is mainly an electrical transmission, which does not require photoelectric conversion. It has a longer service life than optical modules or AOC, so it is basically more than 10 years.

What factors should be considered when choosing an optical module high speed cable manufacturer?

Suggest to consider the industry experience and production scale, flexible to meet the customized development of samples and small orders and timely delivery of batch orders, timely delivery and after-sales service guarantee.

200G-4X50G DAC copper cable | New product release

The longest transmission distance is 3 meters, 1 meter and 2 meters at most, and 0.5 meters. The upper end is a 200G switch and the lower end is a 50G port, which is a common connection method in computing centers.

Why is 25G DAC copper cable more used than 25G optical transceivers now?

25G fiber optic network card interconnection used to use optical module + fiber patch cords, but now uses 25G copper cable instead, because 25G SFP28 DAC cable has lower power consumption, low cost and strong compatibility. So it is used more and more, welcome to inquiry.

What do DAC cable passive and active mean?

• Passive direct attach cable means that the copper cable without signal amplification chip, and transmission distance only 0.2 meters to 5 meters.
• Active direct attach cable means that the copper cable with signal amplification chip, and which can reach a maximum distance of 15 meters.

Why does the DAC cable production workshop need a dust-free workshop?

High speed DAC cables can completely replace optical modules in short-distance transmission, with the advantages of low power consumption and low cost. Because it replaces optical modules, the production process requirements are relatively high. The impedance performance test and differential signal test environment have relatively high dust-free granularity requirements, so a dust-free workshop is needed.

What other colors does DAC cable have besides black?

For twinax direct attach cable, except commonly used black color, there are green, blue, red, orange, yellow, white, etc., which are convenient for customers to distinguish the integrated wiring.

Comparison of the advantages and disadvantages of AOC, DAC, ACC, and AEC cable