For
example, WS-C2960S-24TD-L is 13.3 Mpps.
The figure MPPS expresses
the maximum number of frames per second that can be processed by the device. It
is not dependent on frame size but clearly small frames require higher packet
rates.
To give you an idea of what
this number says:
smallest frames in Ethernet
are 64 bytes in size, taking in account the preamble (8 bytes) and the minimum
inter-frame gap (the last two counts roughly for 20.2 bytes) to fill a GE port
in one direction you need 1484560 frame per second.
10^9 / [(64+20.2)*8] where
8 is bits/byte.
So a number of 13.3 MPPS is
equivalent to [((13.3 M * (64+20.2) * 8)) / 10^9 = 8.95 / 2=4.47] 4.47 GE ports
filled with smallest frames bidirectional.
On the other hand frames of
max size 1518 bytes require 81264 fps to fill a GE port in one direction.
So this number expresses
the forwarding capability of the device.
A non blocking device with
48 GE ports WS-C2960S-48TD-L would require 2 * 1484560 * 48 as MPPS or higher.
Therefore the performance
of a device will be determined by combination of number of packets per sec and
the size of the packet.
