Direct Attach Copper Cable VS Active Optical Cable (AOC)

As one kind of optical transceiver assembly, a direct attach cable (DAC) is used to connect one mobility access switch with another when forming a stack, which can be either passive or active. Since the passive DAC cable contains no active components, it provides a direct electrical connection between corresponding cable ends. This process can also be done by an active DAC cable that is considered active because there are optics and/or electronics embedded within the connectors. Active DAC vs. passive DAC: the active one helps to improve signal quality and provides a longer cable distance. The DAC cable is a fixed assembly that is purchased at a given length.

Seen from the material of the cable, DAC cable can be classified into direct attach copper cable and active optical cable (AOC). Direct attach copper cables can either be passive or active, while AOC cables are always active. The following figure shows leading types of passive and active cable for data center:


As two kinds of commonly-used transceiver assemblies, both direct attach copper cable and AOC cable have their advantages and disadvantages.

What Is DAC Cable?

As the development of fiber technology, someone may deem that copper technology is out of fashion. This is not true for direct attach copper cable. In fact, direct attach copper cable still has its advantages in the market.

DAC cable example 10GBASE-CU SFP+ Active Cable

  • Advantages of Direct Attach Copper Cable

Enough data rate for various applications—Today’s direct attach copper cable can support higher data rates than traditional copper interfaces—from 4Gbps to 10Gbps per channel.

Interchangeability—As the development of copper cable technology, direct attach copper cable is interchangeable and hot swappable with fiber optic modules.

Cost effective—Supporting such multiple protocols as Gigabit & 10G Ethernet, 8G FC, FCoE and InfiniBand, direct attach copper cable is a cost effective solution over optical transceivers.

  • Disadvantages of Direct Attach Copper Cable

The defect of direct attach copper cable is that it is heavy and bulky, making it difficult to be managed. Furthermore, due to the nature of electrical signals, direct attach copper cable is vulnerable to the effects of electromagnetic interference (EMI), such as undesirable responses, degradation, or complete system failure.

What Is AOC Cable?

AOC cable is an alternative to optical transceivers, which eliminates the separable interface between transceiver module and optical cable. It offers a number of advantages over direct attach copper cable.

10GBASE SFP+ Active Optical Cable

  • Advantages of AOC

Greater bandwidth—Needing no equipment upgrades, AOC cable has a throughput of up to 40 Gbps with QSFP+.

Lightweight—Due to its material, AOC cable weighs less than a comparable direct attach copper cable.

EMI immunity—Since the optical fiber is a kind of dielectric (not able to conduct electric current), AOC is immune to electromagnetic energy.

  • Disadvantages of AOC

Compared with direct attach copper cable, the drawback of AOC cable is that it may be a little expensive for customers.


DAC cable and AOC cable are widely applied in storage area network, data center, and high-performance computing connectivity, etc. AOC vs. DAC: the correct choice can be made when you are clear about the advantages and disadvantages of each. Fiberstore provides various kinds of high speed interconnect DAC assemblies including 10G SFP+ Cables, 40G QSFP+ Cables, and 120G CXP Cables.

Related Article:
40G QSFP+ Direct Attach Copper Cables
Active Optical Cable (AOC) – Rising Star of Telecommunications & Datacom Transceiver Markets

Twisted-pair and Direct Attach Twinax Cables Will Become a Trend

Now fiber optic transceivers are commercially available for almost all international and industrial standards, including Ethernet, Fast Ethernet, Gigabit Ethernet, 10Gbit Ethernet. What’s take an important role in this situation is SFP fiber optic transceiver. So let’s take an eye on it. SFP is also called small form-factor pluggable which is a version of Mini GBIC. at first sight, you can find the size is only half of GBIC. It supports data rates up to 10 G. The SFP Transceiver are available with a variety of transmitter and receiver types. What’s more, it is with LC interface. The kind of SFP transceiver module called SFP-10G-SR in Fiberstore is a quite well choice, it is nearly same as Cisco SFP 10G SR. SFP is regarded as a hot pluggable module, this make it Effortless to alter and effortless for upkeep in comparison with conventional modules. It makes the Ethernet network easier to upgrade and sustain. End users can replace a Solitary SFP module Throughout the Procedure Rather of replace the complete board with various modules on it.

SFP+ Transceiver Module

SFP+ twinax cables are copper cables with two SFP+ transceivers attached on either end. This  SFP cable is also known as Direct Attach Cables (DAC). Using twinax cable is significantly cheaper than connecting devices using two 10 Gbps fiber optic transceivers over fiber cable. There are two types of twinax cables. active and passive. In IBM b-type switches only active cables are supported which contain Vital Product Data (VPD) information. Twinax cable is available in length of 1m, 3m, and 5m. Also referred to as twinax, a direct-attach twinaxial cable is very similar to coaxial cable, except for one additional copper conductor core. Both twinax cores are protected by an insulator layer and another metallic conductor surrounding the core pair. Analogous to twisted-pair cables, both cores are twirled together to diminish interference effects from outside sources.

Originally created by IBM for shorter-distance connections, twinax cables offer a cost effective way to interconnect Ethernet devices within racks and across adjacent racks. These cables are usually accommodated into the transceiver housing of a switch or server. Direct-attach 10 Gigabit Ethernet twinax cables have Enhanced small form factor pluggable (SFP+) compatible connectors while 40 Gigabit Ethernet twinax cables deploy Enhanced Quad small form factor pluggable (QSFP+) connectors.

On both data rates, twinax cables are available in the following types. Active: Have components in the SFP+ or QSFP+ housing to improve the signal quality. Usually covers 7 and 10 meters. Passive: Have straight conduction between devices and are available in 1, 3, and 5 meters. for example Cisco SFP-H10GB-CU1M and what SFP-H10GB-CU1M in Fiberstore has same functions with Cisco’s and it also fully compatible with Cisco devices, the same time the price is lower than Cisco’s. Twinax cables have achieved high popularity in data centers because of their high benefit/cost ratio. As an additional advantages, twinax cables present a much lower bit error rate (1 error in 10 E18 bits transmitted) than the IEEE requirements for 10 Gigabit Ethernet connections (1 error in 10E12 bits transmitted). Although the 2004 IEEE 802.3ak standard was the first to introduce 10 Gigabit Ethernet in Twinax cables (10 GBase-CX4), this superseded solution was based on infiniband twinax cables, The twinax cables currently used in 10 Gigabit Ethernet are standardized by the small form format committee standard SFF-8431 and 8461.

Although the Ethernet standardization process has its fair share of politics, the study of its timeline remains a good way to access the networking industry trends over the last three decades. we can see some trends, such as twisted-pair roughly increased ten times its data rate every five years. That pace, however, did not continue in speeds higher than 10 Gbps. Optical fiber had a slightly faster development, being the first media to support data rates higher than 100 Mbps. It also presented the highest longevity among all media. Twinax cables have risen as a viable Ethernet option for 10-Gbps connections.

Because of the higher cost of optical transceivers, fiber is typically employed on links between switches, where higher speeds are required the earliest. High-volume connections, such as server access, depend on lower costs to justify an upgrade to faster data rates. For that reason, twisted-pair and direct-attach twinax cables have been the most popular choices for these connections.

At last, The above information are come from Fiberstore fiber optic manufacturer. Go ahead to check out the details! And the same time there is a good news is that Fiberstore is making a 30% discount about most products, welcome you to visit our online store.

Active and Passive Twinax SFP+ Cable

Twinax cable is a type of cable similar to coaxial cable. The difference is that there are two inner conductors other than on in coaxial cable. This kind of cable is commonly used for very short range high speed differential signaling applications.

Currently there is a copper 10 Gigabit Ethernet cables which comes in either an active or passive Twinax cable assembly and connects directly into an SFP+ housing. SFP+ cable is a twinax cable with SFP+ connector at each end. An active twinax cable has active electronic components in the SFP+ housing to improve the 10 Gig Ethernet signals quality. A passive SFP+ twinax cable is just a direct attach cable and contains no active components to boost signal.

SFP+ Direct Attach Passive Copper cable is suitable for very short distances. They are rated for a range up to 5m and provide a good working solution at a great cost. When the distance between connection points exceed 5m. It is highly recommended to use active cable to ensure signals are transmit all the way through. 5m as the boundary is not absolute, as it may vary from vendor to vendor. For example, FiberStore 10G SFP+ passive cable can be the optimum solution for 10G Ethernet reaches up to 12M.

Except the transmission length, there is indeed no visual difference between active and copper SFP+ twinax cable. SFP+ connectors are the same and the cable jackets are also identical. Most manufactures including FiberStore will have some sort of marking on the cable connector head which will identify the cable as active or passive. But it is also not simply to tell by just looking at it.

The major applications of SFP+ twinax cable are working with network hardware with SFP+ slot. Fiberscope SFP+ cables can be compatible with major brands such as Cisco, HPL, Juniper, Extreme, H3C etc. This type of connection is able to transmit at 10 Gigabit/second full duplex speeds over 12 meter distances. What’s more, this setup also offers 15 to 25 times lower transceiver latency than current 10GBASE-T Cat6/CAT6a/Cat7 cabling systems.

FiberStore Unveils MiniSAS SFFP-8088 Cables

Summary: The FiberStore MiniSAS SFFP-8088 to SFFP-8088 cables are advertised as ideal for dependable, reliable, and cost effective 6 Gb/s storage configurations for networks, servers, workstations and desktops.

FiberStore Co., Ltd has launched the MiniSAS SFFP-8088 to SFFP-8088 cables series which is designed for high performance networks, servers, workstations and desktops. This durable SAS cable features an External mini-SAS (SFF-8088) connector and an External mini-SAS (SFF-8088) connector, and supports data transfer rates of up to 6 Gbps.

As you might expect, the more lanes the faster speed, Mini-SAS is like traffic moving on 4 lanes on the highway instead of just 1 lane. Mini-SAS offers more “Lanes” for data to travel, providing the ability to reach higher speeds. Just like the SATA/eSATA interface, mini-SAS offers the convenience of a one cable connection. However, in a multi-drive SATA/eSATA solution which, only offers one lane for four drives to send/receive data on, mini-SAS provides four separate lanes so each drive can deliver its maximum capable data transfer rate.

Now you can use one or more mini-SAS equipped external storage enclosures like the OWC Mercury Rack Pro for greater speed, protection, or both compared to single channel multi-drive eSATA RAID or eSATA Port Multiplier solutions.

“This durable SAS cable features an SFF-8088 (external mini-SAS) connector, and supports data transfer rates of up to 6 Gbps.” comments Thorndike, FiberStore product manager. “Unlike SFF-8087, where the top cards often have four or six connectors, SFF-8088 usually comes with only one or two connectors per controller. This is because a single SFF-8088 connector on a SAS Expander-enabled controller can connect to a large SAS Expander-enable enclosure, which can then be daisy-chained.”

The SFF-8088 cables are currently available in 6 Gbs external or 3 Gbs internal and far-out assembly types. SFF-8088 with power are also in stock. Custom Mini-SAS cables are available in various lengths and other options. Contact for more information by calling 86-755-83003611, email, or visit