MPLS vs SD-WAN

The main difference between a VPN (Virtual Private Network) and an MPLS (Multiprotocol Label Switching) network comes down to how they achieve network segmentation and access control:

A VPN provides connectivity over a shared network, like the public internet, by establishing an encrypted tunnel between endpoints. This allows remote users or branch offices to access private corporate resources. VPNs leverage identity and passwords for access control and traffic encryption for data security when traversing untrusted networks.

In contrast, MPLS is a mechanism to forward traffic on dedicated, private telecom circuits installed between data centers and office sites. MPLS separates traffic using labels rather than encryption, optimizing transport across the core MPLS network. It then implements access controls at the network edge much like VLANs segment a local area network. MPLS also prioritizes certain applications over others.

In essence – VPNs are software-defined overlays that maximize security, while MPLS utilizes physical isolation and traffic engineering. VPNs suit remote access while MPLS excels at inter-office connectivity. However, growing SD-WAN adoption is replacing MPLS SITE-to-SITE connectivity with dynamic policy enforcement. MPLS lacks agility while VPNs and SD-WAN suit the cloud era.

Read: Replace VPNs with ZTNA Next

Yes, MPLS is still widely used today for enterprise networking particularly connecting data centers and office sites. Though other technologies like SD-WAN are quickly emerging, many major enterprise and carrier networks still rely extensively on legacy MPLS architecture. There are a few key reasons:

Firstly, huge investments have been made over decades building sophisticated global MPLS networks. Ripping and replacing this infrastructure is extremely complex and costly. While MPLS may seem outdated, it delivers reliable and consistent performance between fixed end points. MPLS Quality of Service, Service Level Agreements, and traffic management capabilities enable strong reliability and uptime between locations.

Secondly, MPLS offers natively integrated security mechanisms for segmenting and isolating traffic between business sites. This remains a critical capability for many financial, healthcare and government agencies with strict compliance controls. MPLS hardware also integrates well with existing security stacks.

Finally, the technology is deeply entrenched across networks, systems monitoring, and processes. Rearchitecting requires overcoming massive inertia. Weaning from MPLS requires re-training staff across IT teams as well.

So for the above reasons major commitments to MPLS persist, even as SD-WAN and SASE solutions gain momentum as the next generation enterprise WAN connectivity approach. It will take years for MPLS to fade away, especially in regulated sectors.

An MPLS cloud refers to the core network infrastructure that routes traffic between endpoints using Multiprotocol Label Switching (MPLS) technology. The MPLS cloud sits between customer edge routers at different locations. It provides private, high capacity transport across metro, regional or global distances.

Inside an MPLS cloud, routers don’t use typical IP routing. Instead they assign labels to ingress traffic from customer premises. Packets are then forwarded based solely on these labels following predetermined label-switched paths (LSPs). Labels get removed when exiting the cloud. This allows accelerating routing using simple table lookups rather than lengthy IP analysis.

The MPLS cloud forms the backbone connecting enterprise offices, data centers, call centers and other sites. It often overlays higher-level protocols like VPLS or VPWS to deliver additional services. Carriers build their IP/MPLS backbone to offer connectivity and reliability guarantees through SLAs to enterprises. MPLS centralizes control but it lacks agility.

While MPLS clouds enable large-scale private networking and reliability between sites, alternatives like software-defined WAN overlay services can achieve similar connectivity over cheaper public broadband links. As enterprises adopt SD-WAN, the dedicated MPLS cloud is being replaced by dynamic policy-based overlays.

The main difference between VPLS (Virtual Private LAN Service) and MPLS (Multiprotocol Label Switching) is that VPLS is a Layer 2 VPN service delivered over an MPLS network.

MPLS provides efficient packet transport and traffic engineering across Wide Area Networks. It works by establishing Label Switched Paths across the service provider core. However, MPLS only handles Layer 3 connectivity out of the box.

VPLS brings Layer 2 semantics on top of MPLS transport to offer multipoint Ethernet bridging. This creates a unified broadcast domain connecting geographically dispersed sites. VPLS replicates frames across MPLS paths to appear like a traditional switched LAN.

Essentially, VPLS gives enterprises a software-defined Layer 2 overlay for connecting data centers, offices and multi-tenant sites across metro regions. The MPLS core provides the reliable underlay for pseudowire transport between VPLS network edge devices.

While both are fading against SD-WAN solutions, the difference remains – MPLS enables private IP routing across WAN links while VPLS specifically delivers an extended Layer 2 segment over those same MPLS carrier networks. They build on each other.

MPLS Segment Routing is an emerging MPLS extension for traffic engineering that aims to improve routing scalability, flexibility and programmability.

With traditional MPLS, Label Switched Paths are configured explicitly on every router in the end-to-end path across the network. This becomes complex to operate at scale. Segment routing takes a source-routing approach – sending packets with a stack of labels based on the desired path.

Each label corresponds to a network segment, which could be a router interface or logical grouping. Routers process the next label in the stack to identify the appropriate path across segments towards the destination. This approach centralizes path decisions rather than distributing full topology awareness.

Segment routing vastly expands the number of eligible paths, allowing route optimization on-demand. It also supports binding policies and telemetry data to route computation for smarter traffic steering. Overall, segment routing aims to deliver agility, automation and simplified management to MPLS infrastructure – which lacks intrinsic intelligence. But it remains constrained alongside SD-WAN solutions.