H-VPLS: A Scalable and Efficient Solution for Enterprise Connectivity

H-VPLS: A Scalable and Efficient Solution for Enterprise Connectivity

For organizations with multiple locations or sites, a reliable and efficient virtual private network (VPN) technology is essential for ensuring secure and high-speed connectivity. H-VPLS (Hierarchical Virtual Private LAN Service) is an extension of VPLS (Virtual Private LAN Service) that can provide a more scalable and efficient solution for large-scale deployments.

Hierarchical Virtual Private LAN Service ( H-VPLS)
Fig 1.1- Hierarchical Virtual Private LAN Service ( H-VPLS)

💻 Table Of Content

1. What is H-VPLS ?

H-VPLS (Hierarchical Virtual Private LAN Service) is a type of virtual private network (VPN) technology used to connect multiple locations or sites within a single organization. It is an extension of VPLS (Virtual Private LAN Service) that provides a more scalable and efficient solution for large-scale deployments.

2. Benefits of H-VPLS

The hierarchical architecture of H-VPLS divides the network into multiple layers, with each layer responsible for a specific set of functions. The top layer is responsible for controlling the overall network, while lower layers handle traffic forwarding and aggregation. This architecture allows H-VPLS to support large numbers of sites and users, while maintaining efficient traffic routing and low latency.

H-VPLS also provides a more flexible solution for network expansion. As new sites can be added easily without requiring changes to the existing infrastructure, organizations can easily scale up their network to meet changing needs without having to invest in costly upgrades.

  • Reduces the number of PseudoWires in full mesh: H-VPLS reduces the burden on core devices by limiting the number of PseudoWires that must be in a full mesh.
  • Adds a hierarchical aggregation layer: H-VPLS helps improve the scalability of the control plane by adding an aggregation layer.
  • Reduces the size of the MAC table: When combined with MAC in MAC stacking, H-VPLS can reduce the size of the MAC table.

3. H-VPLS in Action

H-VPLS is commonly used in enterprise networks to provide high-speed, reliable connectivity between geographically dispersed sites.

It can also be used to provide access to cloud-based applications and services, and to support real-time applications like video conferencing and streaming media. 

Case studies have demonstrated the effectiveness of H-VPLS in providing secure and reliable connectivity for large-scale deployments.

4. The Pros and Cons of Using H-VPLS

When working with H-VPLS, there are certain advantages and drawbacks to consider. The split horizon rule is not followed, which means that any traffic arriving on a spoke pseudowire is forwarded to all other PseudoWires (spoke and meshes) and to local circuits. 

This leads to the need to run STP (Spanning Tree Protocol) across the network by the Service Provider in order to avoid loops.

Complexity: H-VPLS can be complex to configure and manage, requiring specialized knowledge and expertise.

Cost: While H-VPLS can be cost-effective in some cases, it may require significant investment in hardware and software to implement.

Network congestion: H-VPLS may be prone to network congestion, particularly if there is heavy traffic between sites.

Vendor lock-in: H-VPLS may require the use of proprietary hardware and software from a single vendor, which can limit flexibility and increase costs.

Limited reach: H-VPLS may not be a suitable solution for organizations with widely distributed sites or remote workers.

Scalability: H-VPLS offers a hierarchical architecture that can support a large number of sites and users, making it a scalable solution for enterprise networks.

Efficiency: The hierarchical architecture of H-VPLS allows for efficient traffic routing and low latency, which can improve network performance.

Flexibility: H-VPLS provides a flexible solution for network expansion, as new sites can be added easily without requiring changes to the existing infrastructure.

Cost-effective: H-VPLS can be more cost-effective than traditional WAN technologies, as it can reduce the need for expensive leased lines.

Security: H-VPLS provides a secure solution for enterprise networks, as it allows for private connectivity between sites.


VPLS (Virtual Private LAN Service) and H-VPLS (Hierarchical Virtual Private LAN Service) are both powerful technologies used to create virtual private networks (VPNs) that allow multiple sites to connect and communicate as if they were on the same LAN (Local Area Network). But, how do these two technologies differ

The primary difference between VPLS and H-VPLS lies in their architecture. VPLS utilizes a flat architecture, where all sites are connected to a single virtual switch. On the other hand, H-VPLS uses a hierarchical architecture, where sites are connected to different virtual switches at different layers

Fig 1.2- VPLS Vs H-VPLS

6. Conclusion

The flat architecture of VPLS provides simple and cost-effective implementation, making it a great choice for small businesses or organizations with limited resources. It also provides a simple way to scale as the network grows.

H-VPLS, on the other hand, offers several advantages over VPLS, such as improved scalability and better performance. Additionally, it allows network administrators to more efficiently manage their networks, as it enables them to prioritize certain types of traffic and make changes to the network with minimal disruption.

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