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Switch Fabric Front Module
Plexus 9000 Planning and Engineering Guide
Issue 2, April 23, 2004
Section 130-120-300
5-98
5.7.3.7
Segmentation and Reassembly (SAR) Controller
There is a ATM Adaptation Layer 5 (AAL5) SAR on each switch fabric
module. This SAR interfaces to the PCI bus that connects to the SP/TM
port on the switch fabric and to the APC. The SAR performs the
conversion from/to cells and the SAR is used as a communications
transport between modules.
5.7.3.8 System
Controller
(SYCOR)
The SYCOR communicates to all the Maintenance Link Bus Adapters
(MLBAs) on the IOMs . It communicates operational status from the
IOMs to the SP. The SYCOR monitors the operational status register and
interrupts the SP on changes.
5.7.3.9
Parallel In, Serial Out (PISO) Interface
The PISOs convert the parallel data of the switch fabric back to serial data
for the IOMs.
5.7.3.10 Redundancy
Control
The SP/TMG and SW/FAB modules are treated as one entity for the
purposes of failover. For example, if a switch fabric fault is isolated, then
a failover of both modules will be initiated, and the ATM cell interfaces
will start receiving from the former protection switch fabric.
In addition, when an I/O module failover occurs, a message is sent to the
IOM’s processor, so that it will change the system processor with which it
is communicating.