CCIE SP MPLS FAQ: Cell-mode MPLS Operation

CCIE SP MPLS FAQ: Cell-mode MPLS Operation

ccie-sp-mpls-faq-cell-mode-mpls-operation

Figure: SuperCell Network—ATM Implementation

Q1. Because IP packets cannot be exchanged directly between two adjacent

Answer: A control-VC is necessary so that control plane information can be exchanged.

Q2. What is an LC-ATM interface?

Answer: Any interface on a router or ATM switch in which the VPI/VCI values are assigned through an MPLS control protocol.

Q3. Which label-distribution method is utilized across an LC-ATM interface?

Answer: Downstream-on-demand label distribution.

Q4. Which label-allocation method does a cell-mode implementation use?

Answer: Ordered control label allocation.

Q5. Which label retention method does a cell-mode implementation use?

Answer: Conservative label retention.

Q6. What is the benefit of using VC-merge?

Answer: Using VC-merge reduces the amount of label space an ATM-LSR requires.

Q7. Why are labels not distributed to upstream neighbors without having received a label mapping from a downstream neighbor?

Answer: To make sure that a complete LFIB entry is available to facilitate correct label switching through the ATM switching matrix.

More Resources

About the author

Prasanna

Leave a Comment