Cisco PSA Microcode MIB - Overview

The PSA is the Packet Switching ASIC used 
in module like engine 2(E2) line cards in GSR
for IP and MPLS packets forwarding. The PSA 
performs IP and MPLS packet forwarding at 4 Mpps. 

The list of features supported by the PSA 
includes (but is not limited to):
- Input and Output ACLs
- Frame Relay Switching
- PIRC
- MPLS VPN
- BGP policy accounting
- IP packet coloring
- Sampled Net flow
- ATM over MPLS.
- Source MAC Accounting.
- Unicast RPF

Note that all the features are not 
supported simultaneously on a module. 
Each microcode bundle/set can support 
one or a limited number of the features 
listed above. Each feature has a priority.  
When a feature (ACL, Sampled NetFlow) is 
enabled through the CLI, the higher 
priority feature will take precedence 
over the lower priority feature.  The 
microcode for the lower priority is 
removed and cleaned up.  The higher 
priority microcode will be loaded.  
Later, if the higher priority feature 
is removed, the lower priority microcode 
will be loaded again.

This MIB contains information about the microcode 
bundles on modules like  E2 Line Cards(LC) in GSR.
Since microcode reload is a service interrupting 
event, this MIB also defines a notification to
inform management stations that such an event has
taken place.