Clarifying the misconceptions...
IT leaders have a host of options when considering the best technology for connecting their corporate network. Whilst MPLS networks have been the established private network of choice for some time, increasingly we see network providers recommend VPLS as a “better” alternative. So what is the real difference? We delve beneath the surface...
MPLS and VPLS defined
Multiprotocol Label Switching (MPLS) is a type of data carrying technique for high-performance telecom networks. It directs data from one network node to the next based on short labels rather than 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 distinction
Whilst MPLS VPN and VPLS are very much based on the same underlying MPLS technology, they are two distinct products, designed for two distinct purposes.
MPLS enables a service provider to provision cost effective and flexible ‘Virtual Private Networks’ across a shared core network infrastructure whilst utilising a choice of last mile technologies.
VPLS enables a service provider to extend a Layer 2 network across geographically dispersed sites using a shared core network infrastructure, but can only utilise an Ethernet last mile technology.
So why then, is VPLS marketed as a “better” alternative to MPLS?
The VPLS proposition
There are two misconceptions we often hear about VPLS technology.
MISCONCEPTION NO 1: “VPLS is faster”
Some providers suggest that VPLS is faster because it uses Layer 2 switching rather than Layer 3 routing. However, when VPLS is run over MPLS, you actually add a VPLS header to each packet so arguably there is additional overhead. Plus, with today’s more advanced routers and switches, there is no noticeable difference between Layer 2 switching and Layer 3 routing anyway.
MISCONCEPTION NO 2: “VPLS is better at routing”
VPLS does not actually perform any routing, it 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 lookups which could actually have a detrimental effect on performance.
So, if VPLS is not faster or better at routing, what are the benefits? It all comes down to what you are trying to achieve.
Typical uses of VPLS
Spanning Layer 2 networks provides support for applications that cannot be separated by a standard Layer 3 routed network. An example might 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 where a company wants a “wires only” solution and has the in-house expertise and desire to deploy and manage routers and routing protocols themselves.
Requirements before solutions
The reality is that you do not need to choose between MPLS or VPLS as these are usually carrier technologies that are hidden from the customer by the ISP. Each technology has its place and it is not typically a choice of one over the other. A reputable network provider will design your solution around your specific requirements – and never offer a solution before understanding your individual business needs.
Bistech provides straightforward advice to make complex technical solutions simple. We tailor our services to every customer’s needs and have been providing MPLS, VPLS and converged MPLS & VPLS solutions for more than a decade. Call us for a no-obligation discussion on 03330 11 22 55.