Plexus 9000 Planning and Engineering Guide
Ethernet Network Access Module
Section 130-120-810
Issue 2, April 23, 2004
Telica, Inc.
5-211
5.19.3.6 GIGSTER
The GIGSTER implements the maintenance link functionality of the MLBA
(Maintenance Link Bus Adapter), which provides a serialized point-to-point
interconnect between the SF module and each Network Access module, and
its microprocessor. This link is used to reset a module, detect CLEI code,
control the LEDs located on the module, download images to the
processor’s memory, program the circuit switch registers and communicate
operational status to the SP. It also provides a bridge between the PCI bus
and the non-PCI-bus-based peripherals, such as the MACs, forwarding
engine and APC devices.
5.19.3.7
Microprocessor, Memory Bus Controller and Memory
The processor section has a microprocessor with memory and a
microprocessor controller for controlling the module. Each module also has
an EEPROM that contains the CLEI code for the module.
5.19.3.8
Segmentation and Reassembly (SAR)
There is a stand-alone Segmentation and Reassembly (SAR) unit on the PCI
bus of each module to provide the microprocessor a means of
communication to the SF module.
5.19.3.9 Power
Each ENA module has its own DC-to-DC converter (not shown in block
diagram), which converts the 48 volts supplied from the backplane to the
local voltages required (3.3Vdc, etc.).
5.19.3.10
Clocks and Synchronization
Clock and framing information is received from the SP clock circuitry. The
Maintenance Link, ATM switch fabric and line interfaces all operate
synchronously to the BITS timing supplied to the SP clock circuitry. The
clock control and distribution circuitry of the IOM distributes these on the
module.
5.19.4 Redundancy
The ENA module is installed in slots I/O-8 and I/O-10. The module in
I/O-8 is the active/primary module and the ENA module in I/O-10 is the
standby/secondary module. The front modules are paired with the rear
modules that provide the physical interfaces the network via Layer 2 or 3
hubs, routers or switches.