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T320 Switch Interface Boards (SIBs) Description


The Switch Interface Boards (SIBs) provide the switching function to the destination FPC (see Figure 1). The SIBs create the switch fabric for the router, providing up to a total of 385 million packets per second (Mpps) of forwarding.

Three SIBs are installed in the T320 router. The SIBs are located at the center rear of the chassis in the slots labeled SIB0 through SIB2 (top to bottom).

SIB0 acts as a backup to SIB1 and SIB2. If a SIB in slots SIB1 or SIB2 fails or is removed, SIB0 becomes active. A slight degradation in performance might occur. When the SIB in slots SIB1 or SIB2 is replaced or reinstalled, it will become active again and SIB0 reverts to backup. The router will regain full forwarding capacity.

SIBs are hot-insertable and hot-removable.

Figure 1: T320 SIB
T320 SIB

Each SIB consists of the following components:

  • Switch Fabric ASICs.

  • High-speed links (HSLs) to each FPC.

    Each Type 1 FPC and Type 2 FPC has one dedicated ASIC with five high-speed links that connect to the three SIBs:

    • One high-speed link connects to SIB0.

    • Two high-speed links connect to SIB1

    • Two high-speed links connect to SIB2.

    Each Type 3 FPC has two dedicated ASICs with five high-speed links that connect to the three SIBs.

  • Three LEDs located on the SIB faceplate that display the status of the SIB.T320 SIB LEDs describes the functions of the SIB LEDs.

  • SIB online/offline button, located on the SIB faceplate.