PXF4336 Datasheet, PDF (98/425 Pages) Infineon Technologies AG – ABM Premium ATM Buf fer Manager

ABM-P
PXF 4336 V1.1
Functional Description
3.5.1.1 Example Network Configuration
Usually, the rate of an ABR connection is determined by the smallest bottleneck in the
network leaving unused bandwidth in some of the links. This bandwidth can be used in
turn by other ABR connections, leading to a very efficient overall usage of network
resources.
In the example of Figure 3-36, five connections with different source and destination
points are traversing four switches.
Assume the following scenario:
Connections 1 to 4 are active ABR connections and connection 5 is a high priority CBR
connection which is initially inactive. The four ABR connections ramp up until the
bandwidth of the common bottleneck in Switch 2 is used up.
At an instant in time, CBR connection 5 becomes active and as a result, ABR connection
4 experiences severe congestion at the common bottleneck in Switch 4. While
connection 4 reduces its sending rate, the bandwidth it had previously used becomes
available along its path. In particular, at the bottleneck in Switch 2 bandwidth becomes
available which is claimed by the other ABR connections.
D1
D3
S1
Switch 1
Switch 2
Switch 3
Switch 4
D4
S3
S2
D5
S4
D2
S5
S1..S5 = Connection Sources
D1..D5 = Connection Destinations
= Bottlenecks
Figure 3-36 Example Network Configuration
Data Sheet
98
2001-12-17