linecard flow chart

johnny_jiang

                                Don't count on it, it's irresponsible.:)
The only things that really differentiate one
line card from another are the physical layer interface module (PLIM)
and the Layer 3 Forwarding Engine.
Each LC can be divided into three major sections:

• 
  Physical Layer Interface Module (PLIM) - This is the hardware module
  that terminates the physical connection (media dependent; therefore,
  Asynchronous Transfer Mode (ATM), Packet-over-SONET (POS), and Fast
  Ethernet)
  
• 
  L3 Switching Engine
  - This forwarding engine actually prepares packets for transmission
  across the switching fabric to the destination LC. It handles L3
  lookups, rewrites, buffering, congestion control, and all L3, QoS
  features. Five types of packet forwarding engines exist, namely,
  engines 0, 1, 2, 3 and 4. Line cards as of this writing are classified
  by the packet forwarding engine type described in the table below.
  
• 
  Fabric Interface - The Fabric Interface ASIC (FIA) prepares the
  packets for transmission across the switching fabric to the destination
  LC. It takes care of fabric grant requests, fabric queuing, per-slot
  multicast replication, and so on.
  

Inbound Linecard:
Packet inbound ACL -> Qos(classification/CAR) -> Forwarding (PBR and default) -> Fabric interface
Outbound Linecard:
IP wccp -> NAT -> Outbound ACL -> QoS (VOQ)
               
               
               
               
               
               
               

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