Cisco Systems 8600 Series manual VBR.3

Traffic Policing Examples

Figure 7-20shows a VBR.3 connection policing example, with policing set to 3, and Leaky bucket 2 shown as 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. 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.

Figure 7-20 VBR.3 Connection, Policing = 3, with Bucket 2 non-compliant

Connection setup

and compliance status:

VBR.3

Policing = 3

Bkt 1 depth < CDVT(0+1)

Bkt 2 depth > BT + CDVT

5	4		3	2	1
CLP=1		CLP=0	CLP=1	CLP=0		CLP=0

5	3
CLP=1		CLP=1

CLP(1) cells compliant with Leaky Bkt 1, admit to network

Time	4
			CLP=0
interval
variations		CLP(0) cells
+		compliant with
CDVT(0+1)
Leaky Bkt 1		Leaky Bkt 1
		are applied to
PCR(0+1)		Leaky Bkt 2
Leaky Bkt 1
discards

2 1

CLP=0 CLP=0

+

BT+ CDVT

Leaky Bkt 2

SCR

4	2		1
CLP=0		CLP=1		CLP=1

Two CLP(0) cells, 1 and 2, are shown as non-compliant with the BT + CDVT limit of Leaky Bkt 2. With policing = 3, the cells are tagged as CLP=1 and admitted to the network.

if depth >

CDVT(0+1)

S6350

7-34Cisco BPX 8600 Series Reference