Hub and Spoke MPLS for Consolidated Video Services

400-007 By islever Editorial Last updated

End-to-end IP traffic flow in a feature-rich environment Resilient, scalable, and secure modular network design based on constraints (such as technical, operational, application, and business constraints) to support applications on the IP network (such as voice, video, backups, data center replication, IoT, and storage)

Short answer

B Use Layer 3 MPLS VPN hub and spoke to route branch-to-hub video traffic efficiently with provider-grade QoS, avoiding the impracticality of a full mesh for 200 sites.

Question

A business wants to refresh its legacy Frame Relay WAN. It currently has product specialists in each of its 200 branches but plans to reduce and consolidate resources. The goal is to have product specialists available via video link when customers visit the nationwide branch offices. Which technology should be used to meet this objective?
  1. DMVPN phase 1 network over the Internet
  2. Layer 3 MPLS VPN hub and spoke Correct Answer
  3. Layer 2 VPLS
  4. Layer 3 MPLS VPN full mesh

Key Takeaways

The main trap is confusing 'consolidation' with 'distributed availability'. Consolidation typically means moving resources to fewer, central locations, creating a hub-and-spoke traffic pattern rather than an any-to-any mesh.

This question addresses WAN design for consolidating specialized resources. Layer 3 MPLS VPN hub and spoke is the correct technology to support video links from branches to centralized specialists while managing cost and QoS.

Common mistake: Selecting Full Mesh (D) because it offers the best performance for any-to-any communication. However, it is economically and administratively unfeasible for 200 sites and unnecessary when the traffic pattern is strictly branch-to-specialist.

Expert Analysis

The scenario describes a WAN refresh where product specialists are being consolidated. The critical constraint is the traffic pattern: specialists are available via video link when customers visit branch offices. This implies that traffic flows from a branch office (customer location) to a centralized or regionalized hub (specialist location). There is no requirement for direct, any-to-any communication between branches; rather, the service is delivered from the specialist pool to the customer at the branch.

Option B, Layer 3 MPLS VPN hub and spoke, aligns with this traffic flow. In a hub-and-spoke topology, all spoke sites (branches) route traffic through a central hub (where specialists are located). This design minimizes complexity and cost compared to a full mesh, which would require 19,900 circuits for 200 sites. It also allows the Service Provider to enforce QoS policies essential for interactive video, ensuring low latency and jitter. Comments supporting Hub-and-Spoke correctly identify that consolidation implies centralization of resources, making hub-and-spoke the efficient choice for delivering specialized services to remote locations. Comments advocating for Full Mesh (Option D) misinterpret 'consolidation' as maintaining distributed specialists who need any-to-any connectivity, which contradicts the goal of resource reduction and the specific use case of serving visiting customers.

Official Reference

https://www.cisco.com/c/en/us/products/cloud-systems-management/software-defined-wan.html

This link opens the official vendor documentation in a new tab.

Exam Strategy

When analyzing WAN design questions, always map the traffic flow first. If the scenario involves centralized services accessed by many remote sites, choose Hub-and-Spoke. Only select Full Mesh if there is a clear business requirement for any-to-any direct connectivity between all sites that cannot be mediated by a central point.

Frequently Asked Questions

Why not VPLS for this scenario?

VPLS emulates a LAN segment, requiring full mesh LDP sessions and complex MAC learning. For a simple hub-and-spoke service delivery model, Layer 3 MPLS is simpler, more scalable, and easier to manage.

Does Hub-and-Spoke impact video quality?

Not negatively if configured correctly. MPLS allows the service provider to apply strict QoS policies (PHB, queuing, scheduling) on the hub links, ensuring low latency and jitter for interactive video traffic.

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Discussion 13 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 13

  1. pizdecvsemu 👍 11 Answered D
    I'd select D. I agree, it's not centralization - a branch with specialist and a branch with customer can be in same geo area, it's not optimal to push traffic to a hub.
  2. J_W 👍 4 Answered D
    By deploying a Layer 3 MPLS VPN full mesh architecture, the product specialists in each branch office would be able to establish video links with each other directly. This enables seamless video conferencing capabilities among the specialists, regardless of their location within the network. This approach provides a high degree of flexibility and ensures efficient communication between the product specialists and customers, as they can directly establish video links without relying on a centralized infrastructure.
  3. dvthakore 👍 4 Answered B
    Don't forget that company wants to reduce and consolidate resources. Hence, product specialist will be available only HQ and branch offices will have only L1 engineer or technicians who will do physical work only. Since, there is no need for video link between branch, the only option left is hub and spoke. Hence, Layer 3 MPLS VPN Hub & Spoke is the only option which fits in the requirement.
  4. rijojohn 👍 3 Answered B
    it should be layer 3 mpls vpn hub and spoke
  5. cisco_guy 👍 2 Answered D
    Not enough information to make a clear decision, too many assumptions. Consolidation doesn't mean centralization, it could mean regionalized. I would ask what does consolidation mean and how they plan to accomplish that. Also, VPLS is an option that would allow full mesh connectivity as well. Until the customer gives more specific answers to what consolidation means, I would maintain status quo, FR is full mesh, therefore I would go with L3 VPN Full mesh.
Show 8 more comments
  1. biddid2 👍 2
    Agree, specialist are in nationalwide. It is difficult to ask them to move to headquater for hub-and-spoken. Consolidation may have one specialist in a district rather than a branch, just simular to a regional manager.
  2. schwabenschulle 👍 2
    Well, in my opinion MPLS full mesh is correct. In the question they talk about consolidation not centralization. So maybe in branch A is specialist group A and in Branch B is group B and in C are none. e.g. -
  3. asdfasdf234 👍 1 Answered B
    Answer: B. Layer 3 MPLS VPN hub and spoke The traffic pattern is hub and spoke. Product specialists are being consolidated into central locations, so video calls go from each of the 200 branches to the central hub, not between branches. The design should match that flow. Video needs guaranteed quality. Interactive video is sensitive to delay, jitter, and loss. An MPLS VPN gives SP-backed QoS and SLAs end to end, which the Internet can’t. Layer 3 scales well. The SP handles routing, and 200 sites nationwide is a routine size for an L3VPN. It’s a natural replacement for Frame Relay, which was typically hub and spoke over a private carrier network, now with modern QoS. Why the others are wrong: A. DMVPN Phase 1 over the Internet matches the hub-and-spoke shape, but the Internet offers no QoS or SLA, which is risky for customer-facing video. C. Layer 2 VPLS puts 200 sites in one big Layer 2 domain. Broadcasts and MAC-learning problems make that a poor fit for scale, and nothing here needs Layer 2. D. Layer 3 MPLS VPN full mesh allows any-to-any traffic between branches, which isn’t needed because all video goes to the central specialists. Full mesh adds unnecessary routing complexity and cost.
  4. 12504a3 👍 1 Answered D
    When using MPLS L3VPN for real-time video, avoid Hub-and-Spoke topologies. They strictly force all branch-to-branch traffic through your central data center, causing 'tromboning' that doubles latency and chokes your hub's bandwidth. Instead, use Full-Mesh. It allows branches to route video traffic directly to each other over the provider’s backbone for the lowest possible latency and jitter. Best of all, the provider handles the routing complexity in their core, so your branches still only need a single, simple connection. Because of course this is not possible to handle ourselves 19 900 connections ((200 x 199) / 2).
  5. XalaGyan 👍 1
    Please check the requirements. it has currently 200 branches/sites/specialists. 200 in a full mesh are 200*199/2 circuits. thats insanly expensive in terms of money and administration. B offers the best balance of money, administration and QoE Answer B
  6. sandccie 👍 1 Answered B
    D. Would be ideal for any-to-any video-conf applications. however, it is not practical to run full mesh for 200 locations. A more practical compromise is to run hub-and-spoke for video-conf applications with acceptable latency tolerance.
  7. Seawanderer 👍 1 Answered B
    To me, "reduce and consolidate resources" means having all the resources in a single place. MPLS L3 HUB and Spoke make sense.
  8. LordAndy 👍 1 Answered B
    reduces and consolidate

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