pxf4333 Infineon Technologies Corporation, pxf4333 Datasheet - Page 89

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

is re-adjusted continuously to obtain maximum switch throughput without overloading
the switch port output rate. This principle is called Preemptive Congestion Control, that
is, congestion due to overload is avoided.
Figure 3-33 Scheduler Block Usage at Switch Input
There are two options for scheduler block rate adjustment:
• After each connection setup or trade-in (static bandwidth allocation).
• Backpressure controlled.
3.4.4
The SBS performs a weighted round robin scheduling among the active SBs. As long as
the sum of the configured SB rates is below the service rate of the SBS, each SB
receives bandwidth up to the configured rate, depending on the load in the SB.
The SBS is said to be overbooked if the sum of the configured SB rates is above the
service rate of the SBS. In this case, the SBS behaves like an RR scheduler for the
overbooked SBs, which all receive an equal amount of bandwidth.
The SBS supports up to 128 Scheduler Blocks per direction. In addition to this, a
common real-time bypass queue (with fixed QID = 0) is supported.
Data Sheet
Scheduler Block Scheduler (SBS)
Ingress Port 1 (ABM-3G)
Ingress Port n (ABM-3G)
SB
SB
SB
SB
1
n
1
n
Switch Fabric
Ingress Port
Bottlenecks
Switch
Fabric
89
R
R
R
R
1,1
n,1
1,n
n,n
R
i,j
Egress Port n
Rate through Switch from
Fabric Ingress Port i to
Fabric Egress Port j
Egress Port 1
Switch Fabric
Egress Port
Bottleneck
622 Mbps
Switch Fabric
Egress Port
Bottleneck
622 Mbps
Functional Description
PXF 4333 V1.1
2001-12-17
ABM-3G