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Can DAC High-speed Cables Be Used as Stacked Cables?

Sep. 17, 2021

Switch stacking is not common in network switch connectivity diagrams. A stacked network switch can be managed visually as a single unit, simplifying network configuration and management and increasing network scalability, flexibility and network capacity, provided that the network switch supports stacking.


Currently, some stacked switches can be directly connected to the stack using DAC high-speed cables or AOC active optical cables or optical modules with patch cables, but some switch suppliers claim that stacked switches must use special stacking cables. So what is a dedicated stacking cable and can a DAC high-speed cable be used as a stacking cable or not? Read this article and you will find the answer.

 

What is a stacking cable?

As the name implies, a stacking cable is a cable used to connect multiple stacked switches. The choice of stacking cable will depend on the type of stacking switch, transmission distance, budget and other factors. Below you will find a list of common stacking cables and common stacking solutions for switches.

Compatible Aoc 25g Sfp28 Active Optical Cable

 Compatible Aoc 25g Sfp28 Active Optical Cable

DAC High-Speed Cable / AOC Active Optical Cable

DAC High-Speed Cable/AOC Active Optical Cable is a common cable used to connect network switches to network switches/servers/routers over short distances (less than 30m) and is no exception for stacked switches. In other words, DAC High-Speed Cable/AOC Active Optical Cable can be used as a normal cable to connect network devices for data transmission or as a stacking cable to connect network switches to expand network capacity. Currently, DAC high-speed cable/AOC active optical cable is one of the most cost-effective and convenient stacking solutions. The DAC high-speed cable is popular with users because of its lower cost compared to AOC active optical cables.

 

When to choose DAC high-speed cable / AOC active optical cable? How does stacking work?

When the ports on the front panel of the network switch support stacking and the transmission distance are within 7 metres, you can choose DAC high-speed cable as the stacking cable to connect to the stacking ports; when the transmission distance is within 7~30, you can choose AOC active optical cable as the stacking cable to connect to the stacking ports. Either the DAC high-speed cable or the AOC active optical cable is simply connected to the stacking ports of the two stacking switches by connecting the connectors at each end. Take the FS S3900-48T4S switch, for example, ports 51 and 52 on the front panel are stackable and can be connected to ports 51 and 52 of the switch using either 10G DAC high-speed cable or 10G AOC active optical cable, up to six switches of the same model can be stacked.

 

Optical modules and fibre patch cords/network cables

Depending on the package, speed and transmission distance of the switch ports, choosing the right optical module and fibre optic patch cable or network cable is a common network switch connection solution, and these two combinations can also be used for stacking switches.

40G QSFP+ DAC CABLE

 40G QSFP+ DAC CABLE

When to choose optical modules and fibre optic patch cables? When to choose optical modules and network cables?

The combination of optical modules and cables (fibre optic patch cords/network cables) is suitable for stacking over different transmission distances. Of these, optical modules and network cables are an alternative for stacking over short distances (up to 100 metres). Although DAC high-speed cables and AOC active optical cables are less costly and time-consuming, the combination of optical modules and network cables has a slightly longer transmission distance and is more compatible. When the transmission distance is within 30m~100m, optic modules and network cables are chosen for stacking, when the transmission distance is over 100m, optic modules and fibre optic patch cables are chosen for stacking.

 

Dedicated stacking cables

As the name implies, dedicated stacking cables are cables that are used exclusively for the stacking ports of the switch, rather than for the normal Ethernet ports, making them irreplaceable and irreplaceable for normal connections. In addition, unlike DAC high-speed cables/AOC active optical cables, which have uniform standards and specifications, dedicated stacking cables have different requirements from one switch vendor to another. Currently, the cost of dedicated stacking cables is higher than DAC high-speed cables/AOC active optical cables in the market.

 

When do I choose a dedicated stacking cable?

When the switch vendor specifies that stacking must be done using a dedicated stacking cable, the dedicated stacking cable (i.e. StackWise cable) must be used for the stacking configuration and the connector on the dedicated stacking cable is different from the regular DAC high-speed cable.

 

Can DAC high-speed cables be used as stacking cables?

The answer to this question is clear in your mind after the above introduction. When choosing a DAC high-speed cable as a stacking cable, three conditions must be met: one, the switch's Ethernet port supports stacking, two, the DAC high-speed cable is compatible with the switch's brand, and three, the network transmission distance is within 7 metres.