PXF4333 Datasheet, PDF (115/361 Pages) Infineon Technologies AG – ABM 3G ATM Buf fer Manager

ABM-3G
PXF 4333 V1.1
Operational Description
4.2.3 ABM-3G Configuration Example
In this section, a popular mini-switch scenario (Figure 4-7) is used to describe the most
important points for the software configuration of the ABM-3G. Among other things, the
following fixed assignments can be made in software by the user:
• Assignment of Schedulers to PHYs and programming of Scheduler output rates
• Definition of the necessary traffic classes
• Assignment of the queues to the traffic classes
• Assignment of the queues (QIDs) to the Schedulers (SBIDs)
Assignment of Schedulers and Programming Output Rates
The ABM-3G has 256 Schedulers (128 in the upstream direction and 128 in the down-
stream direction). In this example each xDSL device is assigned to a separate Scheduler
(this guarantees each xDSL device a 2-Mbit/s data throughput without bandwidth restric-
tions caused by the other xDSL devices); then, 255 xDSL devices can be connected.
The 256th Scheduler will be occupied by the E3 uplink to the public network. The assign-
ment of the Schedulers to the PHYs is totally independent and even such a strong
asymmetrical structure as in (Figure 4-7) can be supported. The output rates of the
Schedulers must be programmed in such a way that the total sum does not exceed 622
Mbit/s (payload rate). From the example, the following result is derived: 255 x 2 Mbit/s +
1 x 34 Mbit/s = 544 Mbit/s ≤ 622 Mbit/s.
0 ADSL
1 ADSL
254 ADSL
34 Mbit/s
Uplink
Multiplex
Network
ALP
UTOPIA
E3
2Mbit/s
2Mbit/s
ABM-3G
0
1
2Mbit/s
34Mbit/s
Uni
directional
mode
254
255
= Scheduler, used as virtual PHYs (≠ UTOPIA PHYs)
Figure 4-7 ABM-3G Application Example: DSLAM
Data Sheet
115
2001-12-17