PXF4336 Datasheet, PDF (102/425 Pages) Infineon Technologies AG – ABM Premium ATM Buf fer Manager

ABM-P
PXF 4336 V1.1
Functional Description
3.5.1.3 Source Behavior Overview
3.5.1.3.1 ACR Calculation
The standardized source behavior defines several conditions under which the ACR must
be recalculated.
BRM Cell Receive
The BRM cells received by the ABR source carry the following congestion related
information:
• CI
• NI
• ER
Congestion Indication Bit is set in highly congested nodes
No Increase Bit is set in moderately congested nodes
Explicit Rate is calculated by nodes
Based on this information, the source performs the ACR calculation according to the
algorithm shown in Figure 3-38:
BRM cell received
N
CI = 1?
Y
ACR = ACR – ACR * RDF
NI = 1?
N
Y
ACR = ACR + PCR * RIF
ACR = min(ACR, ER)
ACR = max(ACR, MCR)
ACR = min(ACR, PCR)
End
Figure 3-38 ACR calculation at BRM Cell Receive
FRM Cell Send
Before sending an FRM cell, the ABR source performs the algorithm in Figure 3-39:
Data Sheet
102
2001-12-17