BPX Switch Common Core 3-17
BPX Switch StrataBus 9.6 and 19.2 Gbps Backplanes
BPX Switch StrataBus 9.6 and 19.2 Gbps Backplanes
The BPX switch may be equipped with a backplane that supports either a 9.6 or 19.2 Gbps operation.
The 19.2 Gbps backplane can physically be identified by the card slot fuses on the bottom rear of the
backplane. Further information is provided in the Cisco BPX 8600 Series Reference.
All BPX switch modules are interconnected by the BPX switch StrataBus backplane physically
located between the front card slots and the back card slots. Even though the ATM data paths to/from
the switching fabric and the interface modules are individual data connections, there are also a
number of system bus paths used for controlling the operation of the BPX switch. The StrataBus
backplane, in addition to the 15 card connectors, contains the following signal paths:
• ATM crosspoint wiring—individual paths used to carry ATM trunk data between both the
network interface and service interface module(s) and the crosspoint switching fabric.
• Polling bus—used to carry enable signals between the BCC and all network interface modules.
• Communications bus—used for internal communications between the BCC and all other cards
in the node.
• Clock bus—used to carry timing signals between the BCC and all other system cards.
• Control bus—enables either the A bus wiring or B bus wiring.
All StrataBus wiring is completely duplicated and the two sets of bus wiring operate independently
to provide complete redundancy. Either the A side wiring or B side wiring is enabled at any particular
time by signals on the Control bus.
