what is a backplane

Unanswered Question
May 5th, 2009
User Badges:

Hi. I did some reading on backplanes and from what i gathered it is a bus to connect the router/switch. What i don't understand is what is real purpose/function of a backplane. Forgive me if my question seems very simple.

Thanks in advance for your indulgence.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
route2null Tue, 05/05/2009 - 23:46
User Badges:

You described it yourself. It's a bus. To expand a little it's a medium over which all the components of a device can communicate.

marcusbrutus Tue, 05/05/2009 - 23:57
User Badges:

Sorry, i'm still a bit confused. I know that a bus is used for communication between components. What i don't know is what are its practical usage. I mean, let's say i have a 2960 switch with a certain bus, i have connected the switch to my workstations and everything is working just fine. How or where does the backplane get into the picture?


Hi Marcus

My simple analogy is that I think of the backplane as the mother board/main circuit board of the switch. It allow the CPU, DRAM, FLASH, ASICS communicate within the switch, which facillitate the switch functioning as required/expected.

If all you had inside your switch was a green board with these components and all the rest just plugged into slots on the board with no way to communicate, then all you would have is a pretty hefty paper weight :)

It's probably not the best analogy but it is the way I think of the backplane.

Best Regards,


marcusbrutus Wed, 05/06/2009 - 00:09
User Badges:

Hi. Sorry. I think i finally got it. The backplane is the motherboard in a router/switch right?

deepa.muralidharan Wed, 05/06/2009 - 00:41
User Badges:


As explained, backplane is a circuit biard that connects several connectors in parallel to each other.

Switch backplane generally refers to the switch fabric. When we talk about the switch backplane capacity, this refers to the maximum throughput when the switch is fully in use.

Joseph W. Doherty Wed, 05/06/2009 - 03:38
User Badges:
  • Super Bronze, 10000 points or more

Backplane is the discreet circuitry that allows different computer components to communicate within the system's frame. A good example within a network device would be a chassis system. When you insert a card, it connects to the backplane. Also see: http://en.wikipedia.org/wiki/Backplane

Generically the term backplane also becomes the "glue" for internal system data communication. For instance, on a modern appliance switch, the "backplane" could be a combination of circuit traces and ICs that support communication between switch ports.


This Discussion