MPLS Traffic-eng DS-TE Models | Cisco CCIE Service Provider Exam

MPLS Traffic-eng DS-TE Models

Question

Which three MPLS Traffic-eng DS-TE models are defined by IETF standard? (Choose three.)

Answers

Explanations

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A. B. C. D. E. F.

BEF.

MPLS Traffic Engineering (MPLS-TE) is a mechanism that enables network engineers to manage network traffic flows by controlling the path that packets take through the network. MPLS-TE uses different models to optimize traffic flows, and one of these models is the MPLS-TE DiffServ-aware Traffic Engineering (DS-TE) model.

The MPLS-TE DS-TE model is defined by IETF standards, and it includes several different models that network engineers can use to optimize traffic flows. These models are:

  1. Resource Reservation Protocol (RSVP) with Traffic Engineering Extensions (RSVP-TE) and Automatic Bandwidth Adjustment (ABA) (A-RDM)
  2. Maximum Allocation with Reservation (MAR)
  3. Generalized Reservation with Distributed Resource Reservation Protocol (GRDP) (GRDM)

So the correct answer is A, B, and C. The other options, G-BAM, MAM, and RDM, are not defined by IETF standard as MPLS-TE DS-TE models.

To briefly explain each of the three MPLS Traffic-eng DS-TE models:

  1. A-RDM: This model uses RSVP-TE to set up and maintain Label Switched Paths (LSPs) through the network. ABA adjusts the reserved bandwidth on each LSP dynamically based on network congestion, ensuring that available bandwidth is allocated efficiently.

  2. MAR: This model pre-allocates bandwidth for each LSP based on the maximum bandwidth that the LSP might need, regardless of current network congestion. This ensures that the LSP always has enough bandwidth to support its traffic, but it may result in wasted bandwidth if the LSP does not use its full allocation.

  3. GRDM: This model uses the Distributed Resource Reservation Protocol (DRDP) to distribute the responsibility for reserving and managing network resources among multiple nodes in the network. This enables more efficient use of network resources and better scalability for large networks.