7-32 Cisco BPX 8600 Series Reference
Traffic Policing Examples
Figure 7-18 shows a VBR.2 connection policing example, with policing set to 2, and leaky bucket 2
non-compliant. 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).
In this example (policing set to 2), CLP tagging is not enabled, so the cells that have exceeded the
BT + CDVT limit are discarded. In the example, either the sustained cell rate could have been
exceeded for an excessive interval, or a data burst could have exceeded the maximum allowed burst
size.
Figure 7-18 VBR.2 Connection, Leaky Bucket 2 Discarding CLP (0) Cells
+
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=1
5
CLP=1
3
CLP=0
4
CLP=0
2
CLP=0
1
CLP(1) cells compliant with Leaky bkt 1, admit to network
CLP(0) cells
compliant with
Leaky Bkt 1,
applied to
Leaky Bkt 2
Connection setup
and compliance status:
VBR.2
Policing = 2
Bkt 1 depth < CDVT(0+1)
Bkt 2 depth > BT + CDVT
S6348
C
LP=0
2
CLP=0
1
To network
CLP=0
4
Two CLP(0) cells, 1 and 2, are shown as
non-compliant with the BT + CDVT limit
of Leaky Bkt 2 and are discarded in this
example where policing = 2. With
policing = 3, they would be tagged as
CLP=1 and admitted to the network.
Discard
Leaky Bkt 1
discards if depth
> CDVT(0+1)
