A 14-section interactive guide to MPLS, MPLS-TP, and SR-MPLS as carrier and enterprise WAN transport technologies — how dynamic LDP-signaled MPLS, static OAM-driven MPLS-TP, and source-routed SR-MPLS each build a label-switched path, label imposition and disposition at the edge of the network, label stack types and their use cases, real router configuration examples, and how operators migrate from MPLS and MPLS-TP toward SR-MPLS through a staged, hybrid-network transition — illustrated throughout with 9 real reference diagrams and configuration snippets.
Chapter 1 establishes the fundamentals: what distinguishes MPLS, MPLS-TP, and SR-MPLS as transport technologies, and how all three can coexist on one physical WAN core connecting office, branch, and data-center sites. Chapters 2–3 go inside the label itself — label imposition and disposition at the ingress and egress of a label-switched path, and the different label stack types (simple, segment list, static chain, service identifier) used for different transport and VPN scenarios. Chapter 4 shows the concepts as real router configuration: SR-MPLS traffic-engineering policies with a customer VRF, an MPLS-TP static-LSP configuration, and an IS-IS segment-routing Node-SID configuration. Chapter 5 closes with migration paths and hybrid networks — migration strategy principles, MPLS-to-SR-MPLS and MPLS-TP-to-SR-MPLS migration approaches, hybrid network architecture, and risk mitigation.
Use the Prev / Next buttons at the bottom, or press the arrow keys on your keyboard. Click the ☰ menu button in the top-right to open the table of contents and jump to any section. Each chapter's real reference diagram follows immediately after its text as its own dedicated, full-size slide.
Network engineers and IT infrastructure professionals designing or operating MPLS, MPLS-TP, or segment-routing WAN cores; carrier and service-provider network planners evaluating an SR-MPLS migration; and networking certification candidates building the visual vocabulary to read real label-switching configuration and topology diagrams confidently.
The guide covers 5 chapters: MPLS vs. MPLS-TP vs. SR-MPLS fundamentals, label imposition and disposition mechanics, label stack types and use cases, real-world router configuration examples for SR-MPLS traffic engineering, MPLS-TP static LSPs, and IS-IS segment routing, and migration paths toward hybrid and fully SR-MPLS networks — with 9 real reference diagrams.
MPLS uses a dynamic control-plane protocol like LDP to signal label-switched paths hop by hop. MPLS-TP strips out that dynamic dependency, using static, explicitly-provisioned paths with dedicated OAM for carrier transport circuits. SR-MPLS keeps MPLS label switching but replaces per-hop signaling with source routing — an ingress node imposes an ordered stack of IGP-advertised Segment IDs, removing the need for LDP or RSVP-TE entirely.
Label imposition is when the ingress router pushes a label onto an incoming unlabeled packet as it enters a label-switched path. Label disposition is when the egress router pops that label back off as the packet leaves the label-switched domain, restoring it to its original unlabeled form.
A simple single-label stack for plain LDP or VPN traffic, a segment list of ordered labels for SR-MPLS traffic-engineered paths, a static chain of three or more labels for MPLS-TP transport tunnels, and a service-identifier label layered over an SR- or LDP-signaled path to carry per-service VPN traffic.
Through a staged, hybrid-network approach guided by four principles: non-disruptive coexistence, service-first migration, path-by-path transition, and operational alignment — running the old and new technologies side by side, migrating individual services and paths one at a time, and validating each step before the next, rather than a single disruptive cutover.
Disclaimer: This guide summarizes general transport-networking concepts and reference illustrations for educational purposes only. Always consult vendor documentation, applicable RFCs, and a qualified network engineer for actual production network design and configuration.