pxf4336 Infineon Technologies Corporation, pxf4336 Datasheet - Page 69

• Manufacturer Part Number: pxf4336
• Description: Abm Premium Atm Buf Fer Manager
• Manufacturer: Infineon Technologies Corporation

• DH
3.4.1.3.2 Congestion Indication Thresholds
Congestion indication thresholds are provided to support external flow control
algorithms.
• ABR Congestion Indication
• SB Congestion Indication
• Queue Congestion Indication
3.4.1.3.3 Backpressure Thresholds
• UTOPIA Backpressure Thresholds
3.4.1.4
The ABM-P Buffer Manager contains the following counter types
• Occupancy Counters
• Statistics Counters
Data Sheet
Delta Hysteresis is a traffic class specific factor applied to all maximum thresholds.
The description of the hysteresis mechanism in
details.
Some thresholds are used to indicate congestion to ABR connections (ABRen=’1’) on
a global buffer, scheduler and queue basis. By exceeding one or a combination of
these thresholds EFCI bits of user cells and NI and CI bits of RM cells are set
appropriately. NI is set in a slightly congested situation. NI and CI are set in a heavy
congested situation.
If the scheduler low and high priority buffer occupation exceeds the respective
thresholds the corresponding threshold crossing indication bits for these scheduler
blocks are set to ’1’. The indication is used for the support of dynamic bandwidth
allocation (DBA) protocols.
These per queue thresholds generate a queue specific congestion indication that is
provided to the QCI interface and translated into a serial bit pattern to be processed
by external devices (downstream only).
These thresholds (four in upstream and four in downstream direction) are global
thresholds with respect to the cell buffer fill level and result in backpressure of specific
port groups of the respective UTOPIA receive interface.
These counters reflect the current buffer state and are basic elements in discard,
congestion indication and backpressure mechanisms.
These counters are used for measurements and statistics. Refer also to
Chapter
Counter Classification
3.4.1.9.
Chapter 3.5.1
Chapter 3.4.1.8
provides the details on the ABR support.
69
provides the details on DBA support.
Section 3.4.1.6.5
Functional Description
PXF 4336 V1.1
provides the
2001-12-17
ABM-P