Cisco BPX 8650, Installation And Configuration Manual

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21-50
Cisco BPX 8600 Series Installation and Configuration
Release 9.3.30, Part Number 78-12907-01 Rev. E0, May 2005
Chapter 21 Configuring ATM Connections
Traffic Policing Examples
Figure 21-26 VBR.1 Connection, Policing = 1, with Buckets 1 and 2 Compliant
Figure 21-27 shows a VBR.3 connection policing example, with policing set to 3, and Leaky bucket 2
shown as noncompliant.
Leaky bucket 2 is shown policing the CLP(0) cell stream for conformance with maximum burst size
MBS (as specified by BT), and for compliance with SCR sustained cell rate.
For the policing = 3 selection, CLP tagging is enabled, so the cells that have exceeded the
BT + CDVT(0+1) limit are tagged as CLP=1 cells and admitted to the network.
In this example, either the sustained cell rate could have been exceeded for an excessive interval, or a
data burst could have exceeded the maximum burst size allowed.
CLP(0+1) cells compliant with
Leaky Bkt 2, admit to network
+
SCR
BT + CDVT
Leaky Bkt 2
CLP=1
5
CLP=0
4
CLP=1
3
CLP=0
2
CLP=0
1
+
PCR(0+1)
CDVT(0+1)
Time
interval
variations
Leaky Bkt 1
CLP(0+1) cells compliant with
Leaky Bkt 1, applied to Leaky Bkt 2
Connection setup
and compliance status:
VBR.1
Policing = 1
Bkt 1 depth < CDVT(0+1)
Bkt 2 depth < BT + CDVT
S6349
Leaky Bkt 1
discards if depth
> CDVT(0+1)
CLP=1
5
CLP=0
4
CLP=1
3
CLP=0
2
CLP=0
1
CLP=1
5
CLP=0
4
CLP=1
3
CLP=0
2
CLP=0
1 To network
For policing = 1,
CLP(0+1) cells are
discarded if Bkt 2
depth > BT + CDVT