What is the difference between DAC and AOC?

The difference between Direct Attach Cables and Active Optical Cables

If you are wondering what is the difference between Direct Attach Cable (DAC) and Active Optical Cable (AOC), this article is for you.

Direct Attach Cables

Direct Attached Cables (DAC) are a very common method used for very short-range distances because of the their low-cost. Indeed, they are the cheapest solution to connect network equipment. DAC are the perfect solution to linked switches, servers and storage inside racks. In addition, it is a one part product instead of the usually three part solution (two transceivers and a cable), which reduces the problems associated with dirty connectors.

DAC consume less power compared to Active Optical Cables (AOC) but they are heavier and vulnerable to the effects of electromagnetic interference (EMI).

There are two types of DAC, the passive copper cable for distance from 0 to 5 meters and active copper cable for distance from 5 to 15 meters

     40G QSFP+ to 40G QSFP+ DAC

100G QSFP28 to 4 x 25G SFP28 DAC

           100G QSFP28 to 4 x 25G SFP28 DAC

Active Optical Cables

Active Optical Cables (AOC) are comparable to using transceivers and separated cables. AOC are mostly used to connect switches, servers and storage between different racks inside a data center for example.

They can reach longer distance than DAC, up to 100 meters depending on the data rate and the type of fiber cable used. They are lighter and smaller than DAC, but they are more expensive, which is one of their main drawback. Unlike DAC, AOC are immune to EMI.

100G QSFP28 to 100G QSFP28 AOC

           100G QSFP28 to 100G QSFP28 AOC

40G QSFP+ to 4 x 10G SFP AOC

40G QSFP+ to 4 x 10G SFP AOC

Of course, if you need to reach longer distance you can always choose to use optical transceivers. The distance reached depends on the data rate but it can reach up to 120km for 1G SFP or 40km for 100G QSFP28 transceivers. To know more about optical transceivers you can check our Complete Guide.

Direct Attach Cables Products

10G SFP+ DAC 10G SFP+ to SFP+ DAC OPSFPP-T-xx-P xx= 0,5 to 7 meters
40G QSFP+ DAC 40G QSFP+ to QSFP+ DAC OPQSFP-T-xx-P xx= 0,5 to 7 meters
40G QSFP+ to 4 SFP+ DAC OPQSFP-T-xx-P/SFPP/4 xx= 0,5 to 7 meters
25G SFP28 DAC 25G SFP28 to SFP28 DAC OPSF28-T-X5-PE xx= 0,5 to 5 meters
100G QSFP28 DAC 100G QSFP28 to QSFP28 DAC OPQS28-T-XX-PE  xx= 0,5 to 5 meters
100G QSFP28 to 4 SFP28 DAC OPQS28-T-XX-P/SF28/4 xx= 0,5 to 5 meters

For DAC products, the length and the gauge size can be customized upon request.

Active Optical Cables Products

10G SFP+ AOC 10G SFP+ to SFP+ AOC OPSFPP-F-xx-AK xx= 1 to 100 meters
40G QSFP+ AOC 40G QSFP+ to QSFP+ AOC OPQSFP-F-xx-AKA xx= 1 to 100 meters
40G QSFP+ to 4 SFP+ AOC OPQSFP-F-xx-A/SFPP/4 xx= 1 to 100 meters
25G SFP28 AOC SFP28 to SFP28 AOC OPSF28-F-03-AKT xx= 1 to 100 meters
100G QSFP28 AOC 100G QSFP28 to QSFP28 AOC OPQS28-F-XX-AK xx= 1 to 100 meters
100G QSFP28 to 4 SFP28 AOC OPQS28-F-01-A/SF28/4 xx= 1 to 100 meters

For AOC products, the length and type of fiber cable (single mode, multimode, OM3, OM4,..) can be customized upon request.

For information, Optech products are compatible with major switches and servers brands on the market. You can check all the compatible lists here.

About Optech

Optech is a leading company in developing and manufacturing Optical Transceivers and Cables solutions for Data Center and Telecom market. Since 2001, Optech has been offering accurate lead time and high quality products to customers.

Optech offers a broad range of networking and communication solutions in following categories: Optical Transceivers, SFP, 10G SFP+, 25G SFP28, 40G QSFP+, 100G QSFP28, 400G QSFP-DD, Direct Attach Cables (DAC), Active Optical Cables (AOC), Ethernet Media Converter, Fiber Optical Patchcord, BWDM, CWDM, DWDM Mux/Demux and Repeater products.

For more information you can visit www.optech.com.tw or contact us at sales@optech.com.tw.

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