How does VPLS (Virtual Private LAN Service) compare to MPLS

Making architectural decisions for your enterprise wide area network (WAN) just seems to get harder and harder! Almost every single day, it seems like a new acronym is thrown around. In this post, we’ll help you understand what Virtual Private Line Service (VPLS) is, as well as how it compares with Multiprotocol Label Switching (MPLS), a WAN technology that it shares some similarities with.

What is VPLS?

Virtual private LAN service (VPLS) is an Ethernet-based WAN technology that allows you to connect geographically dispersed Ethernet LANs to each other across an IP or MPLS backbone via a Layer 2 virtual private network (VPN). My god, that is a lot of acronyms!

Let’s simplify things a bit. VPLS allows you to securely connect multiple LANs over the internet, making them appear as if they were all on the same LAN (hence the “virtual” qualifier) even though traffic is moving across a service provider’s network. With VPLS, you are able to extend a Layer 2 network across geographically dispersed sites using a shared core network infrastructure.

A VPLS network consists of three core components: customer edge equipment (CE), provider edge equipment (PE), and a core MPLS network. CE devices are routers or switches that lie at the customer premises. PE devices are routers at the service provider’s network edge where VPN intelligence resides and terminates, and where tunnels are set up to connect to other PEs in point - multipoint format. The core MPLS network resides between PEs and switches traffic based on MPLS labels. The full mesh of MPLS tunnels between PE devices are referred to as a set of “pseudo wires” and makes up the core of the VPLS instance. 

Given this architecture, VPLS offers enterprises the operational cost benefits of Ethernet service with the quality of service (QoS) of MPLS.

Isn’t this similar to MPLS?

Yes, it is.

VPLS has lots of common elements with MPLS service. Like MPLS, VPLS provides similar levels of QoS and network visibility. As mentioned above, VPLS effectively sits on top of an MPLS network with the MPLS acting as the “engine” for traffic routing. Like with MPLS, you’ll need to roll out VPLS with a one carrier approach, using the same carrier at each site within your VPLS network.

However, there are a few distinct differences worth noting that may dictate your WAN architecture choices. VPLS sets up virtualized LAN-like environments with static routing between sites, while MPLS has dynamic routing capabilities that may come in handy in the event of a network outage. 

VPLS places network control primarily on the customer side, while MPLS places network control primarily in the hands of the carrier. With VPLS, each location and device appears to be within the same LAN, using the same range of IP addresses. This approach allows end users to utilize their own equipment and take control of Layer 3 traffic without depending on the carrier for this. Also, because you’re using only one set of IP addresses, troubleshooting any network element changes is simplified a bit. For smaller WANs where control, ease of install, and cost are paramount, VPLS likely reigns supreme.

For larger WANs with more mission-critical traffic (voice or important data services), MPLS may be better suited. MPLS’s self-healing routes provide improved redundancy, and the lack of control it provides comes with less administrative burden and an improved ability to scale across higher site counts. Contrary to what people say, MPLS will continue to rule for a variety of enterprise use cases.

Not sure which WAN architecture is right for your enterprise use case? Request a meeting with one of Lightyear’s telecom experts today, and we can help point you in the right direction.