Product range DAC and AOC cables
DAC cable and AOC cable: DAC vs AOC
A DAC cable (direct attach copper) is a twinax copper cable with the plug of a transceiver on each end and no separate optical module. It is the short, cheap link inside a rack or to the next one. An AOC cable (active optical cable) does the same job with fiber inside the jacket, so it is thinner, lighter and reaches further. ZeroLine Connect supplies both from 10G to 400G, in the SFP+, SFP28, QSFP+, QSFP28, QSFP-DD and OSFP plugs your switches use, coded for the platforms you name and tested before shipping.
- DAC and AOC, the rates we supply
- 10G–400G
- Passive DAC stays inside the rack or the next one
- Metres
- AOC catalogues commonly run this far; the offer states the length
- To ~100 m
- For the switch models you name, then tested in a host
- Coded
Specification
DAC and AOC cables by rate
DAC and AOC cables, 10G to 400G: direct-attach copper inside a rack, active optical across a row.
Cable
- SFP+ DAC or AOC
- SFP28 DAC or AOC
- QSFP+ DAC or AOC
- QSFP28 DAC or AOC
- QSFP-DD or OSFP DAC or AOC
| Cable | Rate | Plug | Where it goes |
|---|---|---|---|
| SFP+ DAC or AOC | 10G | SFP+ both ends | Server to top-of-rack switch |
| SFP28 DAC or AOC | 25G | SFP28 both ends | 25G server or storage links in the rack |
| QSFP+ DAC or AOC | 40G | QSFP+ both ends | Switch to switch, same row |
| QSFP28 DAC or AOC | 100G | QSFP28 both ends | 100G leaf and spine, short runs |
| QSFP-DD or OSFP DAC or AOC | 400G | QSFP-DD or OSFP | 400G ports, the shortest runs in the row |
| DAC cable | AOC cable | |
|---|---|---|
| What is inside | Twinax copper pairs | Multimode fiber, with the optics built into each plug |
| How far | A few metres. IEEE 802.3 sets 40GBASE-CR4 at up to 7 m and 100GBASE-CR4 at up to 5 m. Passive SFP+ DAC follows SFF-8431, treated as a 7 m cable. 25G and 400G passive cables are shorter. | No single IEEE length. Catalogues commonly run from 1 m to about 100 m. The offer states the length we supply. |
| Power | A passive DAC has no laser, so the port supplies very little. An active copper cable draws more. | More than a passive DAC, less than many long-reach optical modules. |
| Bulk | Thicker and heavier, larger bend | Thin and light |
| Noise | Copper can pick up interference | Fiber does not |
| Cost | The lowest way to connect two ports a few metres apart | More than DAC. Usually less than two separate modules plus a patch cord, which is why we use it for the longer short runs. |
| Typical place | Same rack, or the next rack | Across a row, or where a copper cable is too thick to dress |
Reaches for 40GBASE-CR4 and 100GBASE-CR4 are the IEEE 802.3 cable-assembly lengths. SFF-8431 is the SFP+ direct-attach specification. AOC length is catalogue practice, not a standard maximum. Your offer names the length, the plug and the switch it is coded for.
| The link | Use |
|---|---|
| Inside one rack, under about 3 m | Passive DAC |
| Next rack, still within the copper reach for that rate | Passive DAC if it fits the pathway; AOC if the copper is too thick or too stiff |
| Across a row, or anything past the copper reach | AOC, or two optical modules and fiber |
| Between rooms or buildings | Optical modules and fiber. DAC and AOC are not outside-plant cables |
| One 100G port feeding four 25G servers | Ask for a breakout, QSFP28 to four SFP28. We quote it when you name both switch ends |
| The two ports are different switch brands | Say so. Each end is coded for its own host |
| Item | Why it matters |
|---|---|
| Rate and plug | 10G SFP+, 25G SFP28, 40G QSFP+, 100G QSFP28, 400G QSFP-DD or OSFP, or a breakout |
| DAC or AOC, and the length | Copper only works for the short reach of that rate; AOC covers the longer run |
| Switch model and software at each end | The cable is coded so the port accepts it |
| Straight or breakout | A breakout turns one QSFP port into four SFP ports |
| Pathway | DAC needs more room in the cable manager than AOC |
Options
- Passive DAC in the lengths that rate allows
- AOC where the run is past the copper reach or the pathway is tight
- A breakout from one QSFP port to four SFP ports, quoted when you name both ends
- Coding for the switch models at each end
Tests and documents with every order
- Every cable tested in a host before shipping
- Both ends coded for the platforms you name
- Serial-number list with the shipment
- Warranty stated per model in your offer
Terms
Ordering, testing and delivery
Typical terms. Your offer states the exact terms for your order.
- Minimum order
-
One drum of cable, one reel of fiber or one carton of passive components. Mixed BOMs are welcome. Samples for evaluation typically ship in 1–3 weeks.
- Lead time
-
Stock items 5–10 working days. Made-to-order cable typically 2–4 weeks. Large framework lots ship on the agreed rollout schedule. Fiber prices moved sharply in 2026, so every cable offer states how long its price holds next to the lead time.
Fiber and cable prices in 2026 - Test reports
-
OTDR data for every drum of cable, insertion and return loss for every connectorised assembly, loss and uniformity reports for splitters, and our pre-shipment inspection report. Third-party pre-shipment inspection on request, at the buyer’s cost.
- Labelling and packing
-
Drum and carton labels to your scheme: project, lot, route or rack. Export cartons, and wooden or plywood drums for cable.
- Payment
-
T/T with 30% deposit and 70% before shipment, or L/C at sight. Rollouts can run under a framework agreement with staged lots.
Payment terms and trade finance - Delivery
-
FOB Wuhan or Shanghai, CIF to your port, or door delivery where available. Goods from other ZeroLine lines ship in the same consignment when that saves freight.
Shipping and compliance
Keep reading
Guides, solutions and services
- SFP modules When the link is too long for a DAC or AOC cable, use a module and fiber.
- Telecom and FTTx networks Everything between the central office and the home, delivered to your rollout plan.
- Data centers Structured cabling, optics and backup power from one source.
- Fiber-optic cable plants Make optical cable and patch cords in your own country.
- Inspection and test reports Factory tests and our pre-shipment inspection on every lot.
FAQ
DAC and AOC cables: questions buyers ask
What is the difference between a DAC cable and an AOC cable?
A DAC cable is copper twinax with a transceiver plug on each end. An AOC cable is fiber with the optics built into those same plugs. DAC is for a few metres inside a rack. AOC is thinner and reaches further, commonly up to about 100 m. Neither replaces optical modules and patch cords once the run leaves the row.
How long can a DAC cable be?
It depends on the rate. IEEE 802.3 allows up to 7 m for 40GBASE-CR4 and up to 5 m for 100GBASE-CR4. Passive 10G SFP+ DAC follows SFF-8431, a 7 m cable. Passive 25G and 400G cables are shorter. The length on the offer is the one to design to, not the longest number in the standard.
Is a DAC cable cheaper than two SFP modules?
For a short link, yes. One DAC or AOC cable replaces two modules and a patch cord, which is why in-rack links are usually cables rather than optics. The saving shrinks once you need a length copper cannot do.
Can I use a DAC cable between rooms?
No. DAC is a few metres of copper, and AOC is a short indoor jumper. A run between rooms or buildings needs optical modules and fiber, single-mode if it may grow. Our SFP modules page lists the reaches.
Get a matched quote
Quote DAC and AOC cables
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