From the course: MPLS L3VPN Foundation and Implementation

MPLS architecture and components

From the course: MPLS L3VPN Foundation and Implementation

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MPLS architecture and components

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- [Lecturer] Welcome to the MPLS fundamental section of the MPLS L3VPN Foundation and Implementation course. This is the first video, MPLS Architecture and Components. By the end, you will understand the structure of an MPLS network and how labels drive packets forwarding. Let's dive into the foundation of MPLS. MPLS, Multiprotocol Label Switching, revolves around peculiar architecture. It's split into two zones, the edge and the core. At the edge, we have routers that bring traffic in and out of the MPLS network. These are the entry and exit points. In the core, we have routers that handle traffic inside the network. Together they form a system designed for fast, efficient forwarding. Here is the breakdown. Edge routers, known as Label Edge Routers or LERs, sit at the network boundaries. They are the gatekeepers where traffic enters or leaves. Core routers, called Label Switch Routers or LSRs, sit inside connecting the edge. These components work together to create pods, called Label Switch Pods or LSPs, that guide traffic from one side to the other. The architecture hinges on these roles, LERs at the start and end, LSRs in between. Now, how do labels drive packet forwarding? When a packet hits an LER at the network edge, it gets a label, a short tag that defines its path. This isn't about deep routing decision, it's a simple instruction. The packet then travels through the core where LSRs read the label and forward it along the LSR. At each hub, the label keeps things moving fast. No complex lookups, just a quick check and send. At the final LER, the label job is done and the packet exits. The beauty of this setup is control and speed. LER decide the path upfront by adding labels and LSRs follow that plan, switching traffic along LSPs. The architecture, edge, and core, LERs and LSRs, makes this possible, turning a network into a streamlined highway. Labels are the drivers, steering packets exactly where they need to go without delay. To wrap up, MPLS architecture is built on LERs at the edge and LSRs in the core, forming LSPs. Labels drive forwarding by giving packets a fast, predefined route through the network. In the next video, Label Distribution Protocols, LDP and RSVP, explained. We will see how those labels get assigned. Stick around as we build on this foundation.

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