This MIB defines objects related to statistics 
for the usage of switch fabric. The switch fabric
is used by the incoming packets from the line/network
to a interface. Such packets are called ingress packets.
Counters are maintained for number of ingress packets/
octets switched by the switch fabric for each 
interface.
NOTE: These counters are not counting the total number 
of incoming packets and octets for a particular 
interface. Instead only the counts of packets and 
octets that actually use the switch-fabric are being
accounted for by this MIB.  Therefore, the counters in 
this MIB are distinctly different from packet and octet 
counters found in the IF-MIB.