PXF4333 Datasheet, PDF (63/361 Pages) Infineon Technologies AG – ABM 3G ATM Buf fer Manager

ABM-3G
PXF 4333 V1.1
Functional Description
Scheduler Blocks are usually assigned to ports, logical channels, or limited terminated
VPCs, providing the necessary rate adaptation. Section 3.4.3 provides the details.
SB occupancy thresholds are provided for buffer protection in case of SB overload.
3.4.1.2.4 Traffic Classes
The concept of traffic classes is introduced to provide a logical grouping of queues with
common properties, defined by a set of parameters. Each logical queue is
unambiguously assigned to a traffic class and inherits the thresholds and flags defined
therein.
The Buffer Manager supports up to 16 distinct parameter sets for traffic classes in the
Traffic Class Table (TCT). Each parameter set includes thresholds and flags as listed in
Chapter 3.4.1.3.
Figure 3-16 shows the independent assignment connections to queues and of queues
to traffic classes and schedulers.
S c he d ule r
B loc k 0
S c he d ule r
B lo ck 1 2 7
T r a f fic
class 0
T ra ffic
class 1
T ra ffic
class 1 5
V irtu a l C o n n e c tio n to Q u e u e M a p p in g
Q u e u e to S c h e d u le r M a p p in g
Q u e u e to T ra ffic C la ss M a p p in g
Figure 3-16 Queue Assignment to Traffic Classes and Scheduler Blocks
Traffic classes are the principal buffer management concept for Quality of Service (QoS)
differentiation. They are not pre-defined or fixed to the standard ATM service categories.
This allows for configuration of generic or new services (e.g. DiffServ Per Hop Behaviors
(PHB) as defined by the IETF). Along with the queue scheduler concept of scheduler
blocks (see Section 3.4.2.2), a wide range of QoS objectives can be met.
Data Sheet
63
2001-12-17