pxf4333 Infineon Technologies Corporation, pxf4333 Datasheet - Page 79

• Manufacturer Part Number: pxf4333
• Description: Abm 3g Atm Buf Fer Manager
• Manufacturer: Infineon Technologies Corporation

For a given arrival rate
scheduler simply cuts off the low priority traffic assumed in the white bar. The RR
scheduler iteratively divides the output rate into equal shares among the active inputs.
The WFQ scheduler divides the output rate in proportion to the assigned weights
assumed to be proportional to the respective arrival rates.
3.4.2.3
In the context of ATM service categories, it is useful to introduce the concept of guaran-
teed rate. This is the rate which the network must guarantee to the user in order to fulfill
the QoS demands.
Table 3-24
Mapping of connections to stage 1 schedulers depends on the ATM service category of
the connection (also shown in
– Priority 1 RR:
– Priority 2 WFQ:
– Priority 3 RR:
An example of a scheduler with one priority 1 real-time queue (Queue 1) and nine priority
2 non-real-time queues (Queue 2 through Queue 10) is shown in
is shared by a number of connections with different bit rates.
Data Sheet
ATM Service
Category
CBR
rt-VBR
nrt-VBR
GFR
UBR+
UBR
Quality of Service Support
Guaranteed Rates for each ATM Service Category
Guaranteed Rate
PCR
SCR...PCR
SCR
MCR
MCR
none
Figure 3-23
real-time connections (CBR, rt-VBR).
non real-time connections with guaranteed rate
(nrt-VBR, GFR, UBR+)
best effort connections UBR
Figure
shows the repartition of the output rate. The priority
3-22) as follows:
79
Comment
tive bandwidth formulas” assuming small
buffers and taking into account statistical
multiplexing gain.
Guaranteed rate is delivered in complete
uncorrupted AAL5 frames.
Guaranteed rate is always > 0 with queue
connected to the WFQ scheduler, can be 0
for arbitrary long times in low priority RR
scheduler.
Guaranteed rate is calculated with “effec-
Functional Description
Figure
PXF 4333 V1.1
3-25. Queue 1
2001-12-17
ABM-3G