Cisco Systems 8600 Series manual CBR Connection, UPC Overview

Traffic Policing Examples

Figure 7-11 CBR Connection, UPC Overview

CBR Traffic

	Multiple PVCs	Verify
		VPIs,
CPE		VCIs

Cells
per	PCR
sec.
	Time

To UPC for each

individual PVC

Policing

For CBR connections, Leaky Bkt 1 ensures that the combined CLP=0 and CLP=1 cell traffic stays in PCR compliance within the CDVT limits. Leaky Bkt 1 admits compliant CLP cells to the network, and discards non-compliant CLP cells.

Policing: 4 = PCR Policing only	Clumping
5 = off	(Cells arriving early, i.e, at a
	higher than contracted rate)

Cells arriving late

(at a less than

contracted

cell rate)

TAT TAT TAT TAT TAT TAT TAT TAT

(TAT=Theoretical Arrival Time for cells per traffic contract)

Example: Policing = 4

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

Time interval variations

+

CDVT(0+1)

Leaky Bkt 1

5	4		3		2		1		Admit to network
CLP=1		CLP=0		CLP=1		CLP=0		CLP=0

PCR(0+1)

Discards incoming CLP(0+1) cells if Bkt

1 depth > CDVT(0+1). Does not tag cells. If Bkt 1 depth < CDVT(0+1), passes CLP=0 and CLP=1 cells on to network.

Note: The notation 0, 1, and 0+1 refers to the types of cell being specified: cells with CLP set to 0, CLP set to 1,or both types of cells, repectively. For example, CLP(0), CLP(1), and CLP(0+1).

S6341

7-24Cisco BPX 8600 Series Reference