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Can DAC Cables Be Used As Stacked Cables?

Sep. 07, 2022

Switch stacking is not uncommon in today's world of network switches. By "stacking" stackable switches and operating them as a unit, it becomes a quick way to increase capacity and flexibility. Some stackable switches can be stacked via DAC cables, while others must be connected via what the vendor claims are stacking cables. What exactly are stacking cables here? Are they the same as DAC cables? Find out in the following article.

 

What are stacked cables?

A stacking cable, also known in some cases as a stacking cable, is, as the name suggests, a cable used to physically connect multiple stackable switches together. The choice of cable depends on the type of stacking of the switches, the distance of the switches, budget, and other factors. Common stacking cables and alternatives to switch stacking are listed below.


 Breakout 100g QSFP28 To 4SFP28 DAC Cable

  Breakout 100g QSFP28 To 4SFP28 DAC Cable     

DAC/AOC cables

AOC and direct-attached copper cables (DAC cables) are common connection solutions for connecting network switches to switches, routers, or servers for data transfer via data ports. For some stackable switches, DAC and AOC are not only suitable for data transfer, but also as stacking cables. DAC cables are becoming more widely used by significantly reducing the cost of the same length of AOC.


When to use DAC/AOC cables for stacking?

When stackable switches support FPS (Front Panel Stacking, FPS), i.e. stacking via the Ethernet port on the front panel of the switch, the cable carrying the data can be used as a stacking cable. This allows DAC cables or AOC cables to be used.

 

The stacking cable is connected to the Ethernet port on the front panel of one switch, and the other end of the cable is plugged into the stacking port on the opposite row of the other switch. Depending on the type of data port, optical modules and cables or individual copper cables are the usual types of data connections between switches and switches. They also offer solutions for connecting stackable switches.

100G QSFP28 AOC

  100G QSFP28 AOC

Dedicated stacking cables

Dedicated stacking cables are a class of stacking cables that connect to dedicated ports on stackable switches rather than Ethernet ports. They are not like DAC cables with uniform industry standards and specifications. Different switch vendors use their own proprietary special cables to stack their stackable switches. They cannot be reused in other brands of switches or even in other series of switches from the same supplier. Making special stacking cables irreplaceable. As a result, the cost of dedicated stacking cables is typically higher than the other two types of stacking cables mentioned earlier.


When to use a dedicated stacking cable for stacking?

When a stackable switch supports backplane stacking (BPS), a dedicated stacking cable must be used - the switch is stacked via a special stacking module on the switch backplane.

 

Can DAC cables be used for stacking cables?

After reading the above, you probably already have a clear picture of the answer. DAC cables for stacking should meet the following conditions: The switch stacking unit supports Ethernet port stacking, the DAC cable is compatible with stackable switches and the cable length meets the requirements.