MPLS vs VPLS: What's the Difference?

Clarifying Misconceptions

MPLS vs VPLS. Or perhaps better SD-WAN?

IT leaders have many options when considering the best technology for connecting their corporate network. While MPLS networks have been the established private network of choice for some time now, we are increasingly seeing network providers recommend VPLS as a “better” alternative. So what’s the real difference? We dive beneath the surface…

What are MPLS and VPLS?

Multiprotocol Label Switching (MPLS) is a type of data-carrying technique for high-performance telecom networks. It sends data from one network node to the next based on short labels instead of long network addresses, avoiding complex lookups.

Most service providers create a Layer 3 Virtual Private Network (VPN) to segregate and secure customer traffic over a shared MPLS infrastructure. (The term “MPLS VPN” is usually shortened to just MPLS.)

Virtual Private LAN Service (VPLS) is a way to provide (Ethernet only) layer 2 VPNs over an MPLS Wide Area Network (WAN).

Understanding the Difference

While MPLS VPN and VPLS are largely based on the same underlying MPLS technology, they are two separate products, designed for two different purposes.

MPLS offers a service provider the ability to provide cost-effective and flexible “virtual private networks” over a shared core network infrastructure while choosing from the latest-mile technologies.

VPLS allows a service provider to extend a Layer 2 network across geographically dispersed sites using a shared core network infrastructure, but can only leverage an Ethernet last mile technology.

So why then, is VPLS being marketed as a “better” alternative to MPLS?

The VPLS proposal

There are two misconceptions we often hear about VPLS technology.

Misconception 1: “VPLS is faster”

Some providers suggest that VPLS is faster because it uses Layer 2 switching instead of Layer 3 routing. However, when VPLS runs over MPLS, you’re actually adding a VPLS header to each packet, so there’s arguably extra overhead. In addition, with today’s more advanced routers and switches, there is no noticeable difference between Layer 2 switching and Layer 3 routing.

Misconception 2: “VPLS is better at routing”

VPLS does not perform any routing, but simply creates a large Layer 2 network. By creating a large Layer 2 network, you could potentially open up your network to large amounts of broadcast traffic and table queries that can affect performance.

So, if VPLS isn’t faster or better at routing, what are the benefits? It all comes down to what you are trying to achieve.

Typical use of VPLS

Spanning Layer 2 networks support applications that cannot be separated by a standard Layer 3 network. An example could be business applications that need to be located in different parts of the country and require Layer 2 connectivity for high availability or replication purposes.

VPLS is also useful when a company wants a “wire only” solution and has the in-house expertise and desire to implement and manage routers and routing protocols on their own.

First the requirements, then the solutions

The reality is that you don’t have to choose between MPLS or VPLS as these are usually carrier technologies hidden from the customer by the ISP. Every technology has its place and it is usually not a choice over the other. A reputable network provider will design your solution around your specific requirements – never offering a solution until you understand your individual business needs.

Spinae offers clear advice to make complex technical solutions simple. We tailor our services to your needs. Call us for a no-obligation conversation.