Cisco Systems 8600 Series manual VBR Dual-Leaky Bucket Policing Examples, VBR.1

Traffic Policing Examples

VBR Dual-Leaky Bucket Policing Examples

The contract for a variable bit rate connection is set up based on an agreed upon sustained cell rate (SCR) with allowance for occasional data bursts at a Peak Cell Rate (PCR) as specified by maximum burst size MBS.

When a connection is added, a VPI.VCI address is assigned, and UPC parameters are configured for the connection. For each cell in an ATM stream, the VPI.VCI addresses are verified and each cell is checked for compliance with the UPC parameters as shown in Figure 7-14.

The VBR cells are not enqueued, but are processed by the policing function and then sent to the network unless discarded.

For VBR, traffic policing, depending on selected policing option, is based on:

•

•

Leaky bucket 1, PCR and CDVT

Leaky bucket 2, SCR, CDVT, and MBS

The policing options, selected by entering 1-5 in response to the policing choice prompt, are as follows for VBR connections:

VBR.1	CLP(0+1) cells compliant with leaky bucket 1 are passed to leaky bucket 2;
VBR with policing	non-compliant cells are discarded. CLP(0+1) cells compliant with leaky bucket 2 are
	admitted to the network; non-compliant cells are discarded.
set to 1.
VBR.2	CLP(1) cells compliant with leaky bucket 1 are admitted to the network; non-compliant
VBR with policing	CLP(0+1) cells are dropped. CLP(0) cells compliant with leaky bucket 1 are applied to
	leaky bucket 2; non-compliant cells are dropped. CLP(0) cells compliant with leaky
set to 2.
	bucket 2 are admitted to the network; non-compliant cells are dropped.
VBR.3	CLP(1) cells compliant with leaky bucket 1 are admitted to the network; non-compliant
VBR with policing	CLP(0+1) cells are dropped. CLP(0) cells compliant with leaky bucket 1 are applied to
	leaky bucket 2; non-compliant cells are dropped. CLP(0) cells compliant with leaky
set to 3.
	bucket 2 are admitted to the network; non-compliant cells are tagged and admitted to the
	network.
VBR with policing	CLP(0+1) cells compliant with leaky bucket 1 are admitted to the network;
set to 4.	non-compliant cells are dropped. Leaky bucket 2 is not active.
VBR with policing	Policing is off, so there is no policing of cells on ingress.
set to 5.

7-26Cisco BPX 8600 Series Reference