VPLS – Virtual Private LAN Services

If you have not heard of a Virtual Private LAN Service (VPLS) before, we are going to break it down for you. It is a service that businesses use to make their business look more connected, but it can also be used by a private home network. So what exactly is a VPLS and why does it matter?

What Is It?

A VPLS is a service that uses Multiprotocol Label Switching (MPLS) in addition to Virtual Private Networking (VPN) in order to connect two or more LANs that are not actually connected. Appearance-wise, the LANs will look like they are all the same LAN, but it is only in appearance. As a result, the internal routing protocols can be used in separate locations.

It needs a full mesh setup to work effectively. The two ways to achieve mesh connectivity are the Border Gateway Protocol (BGP) and Label Distribution Protocol (LDP). Another option is RADIUS. Through the use of an auto-discovery setup, the network can identify other participating routers within the same VPLS, ensuring that they are cohesively connected.

  • BGP: BGP supplies auto-discovery as well as signalling. It is similar to Layer-3 MPLS VPNs in that each provider edge is configured to the VPLS. Then it uses the BGP to find the other PEs and connect to them.

  • LDP: Unlike with the BGP, with an LDP, every PE router has to be configured to the VPLS in order to use it. They will not be able to auto-discover it, so it will need to be done manually. It will still work; however, it just does not set up quite as cleanly as the BGP does.

  • RADIUS: To use this method, all of the PES needs to be configured to a RADIUS server. When a router wants to join the VPLS, it will need to request authentication through a RADIUS server. The server than keeps track of every PE that tried to join the VPLS, including the ones that did not have the correct password to proceed.

How Does It Work?

VPLS works through the creation of a virtual Ethernet switch at the provider’s edge. The switch will link remote sites together, creating a unified appearance. This happens through the use of your ISP. The ISP builds out the network itself, though the VPLS happens at Layer-2. The consumer still has the controls over the routing and security, which can be important when dealing with sensitive topics.

It works through the use of pseudo-wires, which are an emulation of a point-to-point connection. Instead of the PTP connection, it is using a packet-switching network (PSN). A pseudo-wire works through an MPLS, but it can also use an ATM, which are still used by some ISPs. The PEs that want to participate in the VPLS need to look like an Ethernet bridge in order to connect devices.

Who Uses It?

A VPLS is usually used by businesses that have more than one data center footprint as well as several locations. Regardless of whether they are stores or offices, a unified business will want unified connectivity. These businesses will need a low-jitter, low-latency connection that can be achieved through the use of a VPLS.

It’s Importance

While you might know that businesses might want to use this service to make the entire business to appear on the same LAN, what does this advantage really mean? Businesses like it, because they can have multiple locations use the same CoS/QoS markings and internal routing protocols. Additionally, there is a cost-saving factor at play.

Combining the benefits of an Ethernet connection with the security provided by a VPN, while still using QoS characteristics is a business’s dream. Having multiple sites connected through the same domain can further enhance the level of security that they would hope to get from their business network.

In fact, a VPLS network can handle more than a million MPLS labels, or unique identifiers. It makes it easier for a business to handle multiple access points with the same criteria and level of security, allowing for an easy setup and control.

Bottom Line

When it comes down to it, there are very few instances when a home network would need to utilize a VPLS. This is better suited for businesses that have devices in more than one location. A home network would be better off utilizing a VPN through the router instead of trying to work out the details of a VPLS.

That said, if you are a business with multiple locations, a VPLS is a safe way to connect the entire network along the same LAN. Even if there are technically more than one LANs, it would still look like there was only one. A VPLS can help bring more security to your business while also allowing everyone to be on the same network, regardless of location.