Using the Model 5782 ATM Virtual Network Router
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Dedicated high-performance processors on every frame switching module.
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400 Mb/s full-duplex segmentation and reassembly (SAR) ASIC located on
each frame-switching module to convert frames to ATM cells and vice versa,
using the AAL/5 standard.
Each module attached to a Centillion backplane builds and maintains its own
routing tables for directing traffic. A central supervisor, called the master control
processor (MCP), consolidates these distributed tables into master tables that are
accessible to other modules within a chassis or within a network of Model
5000BH hubs or Centillion 100 switches. In the Model 5000BH chassis, the MCP
is provided by a Model 5724M or 5728M ATMSpeed Switch MCP Module. The
MCP provides the following functions:
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Performs user-to-network interface (UNI) signaling
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Handles the control functions for LAN emulation (LANE) clients
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Provides LANE services (LECS, LES, BUS)
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Handles switch-wide housekeeping functions such as network management
PPX Router Bus
The Parallel Packet Express (PPX) is a redundant bus with four independent
parallel paths that perform at 1 Gb/s between router interfaces.
Model 5782 VNR modules attach to a Model 5000BH chassis with a PPX
interconnection. The PPX backplane interconnection performs the packet-
to-packet transfer from one router installed in the chassis to another router
installed in the same chassis. The PPX interconnection eliminates the need for
segmentation and reassembly (SAR) of packets to cells from an ATM
environment and reduces latency between ATM routers and non-ATM routers
installed in the Model 5000BH chassis.
The PPX backplane allows other routers within the chassis to boot one another
and allows for flash memory card redundancy.
