Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
A switch fabric generally means an architecture that allows multiple concurrent point-to-point data transfers without the need to "share" bandwidth. For example ports 1 and 3 might be exchanging data while ports 2 and 4 are exchanging data too. What's important is ports' 1 and 3 data exchange doesn't "take" any of ports' 2 and 4 data exchange bandwidth, nor do ports' 2 and 4 data exchange "take" bandwidth from ports' 1 and 2 data exchange. NB: not all switches provide fabric to the edge ports, often multiple edge ports share a connection to the fabric.
Switch capacity is often a measure of the switch's fabric bandwidth and the switch's packets per second forwarding capacity. Sometimes a switch's capacity (fabric bandwidth and/or PPS) cannot support all its edge ports running at 100% with any frame size. (An example of this can be seen with the 3750G switches.)
PS:
BTW there are different architectures for switches, some of which might implement head-of-line blocking. I.e. there's more a switch than just its "capacity".
