switch speed question

Tue Feb 24 17:15:24 UTC 2009

Eric Gearhart wrote:
> ....
>
> Note that the traffic to a switch is bi-directional (full duplex) - so
> a 24 port gigabit switch can max out its 32 Gig backplane, if all 24
> ports have a gig coming in and going out (24 X 2 is 48, more than the
> 32 gig backplane).
>
> ....
>   
I think your math is faulty.  While there may be 24G going in and 24G
going out, there is only 24G crossing the backplane.  You can't count a
bit twice (once on in and once on out).  Its the same bit.