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Optimize End-to-End MPLS Networks with Seamless MPLS

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The increased adoption of MPLS within operator networks calls for highly flexible, scalable, resilient and manageable network architectures. Seamless MPLS offers a superior alternative for implementing end-to-end MPLS networks by integrating access, aggregation and core networks into a single MPLS domain. Network operators must consider seamless MPLS for optimizing and improving the efficiency of their end-to-end MPLS networks. MPLS is universally deployed in most Service Provider Core networks and has seen significant adoption within metro networks over the past decade. The metro network is undergoing a transformation driven by increasing demand for video, mobile broadband and cloud services. Network operators need to reduce capital and operational costs and use existing resources more optimally. To achieve these goals, many operators have converged their separate service networks to a single converged services network based on IP/MPLS. In addition, applications like IP/MPLS Mobile backhaul for evolution to LTE as well as business and residential services have extended deployment of MPLS to the metro access network. This has resulted in implementation of very large MPLS networks, with MPLS deployed end-to-end from metro access to metro aggregation to the IP core layers of the network.


MPLS currently offers several features like LDP extensions for inter area LSPs, intra and inter area RSVP-TE, LDPoRSVP and PW switching (Multi-segment PW) which may be implemented to support end-to-end MPLS services. These features do not completely address the flexibility, scalability, resiliency and manageability of end-to-end MPLS networks. Enter Seamless MPLS - An IETF Working Group initiative. Seamless MPLS offers a superior alternative for implementing end-to-end MPLS networks. It describes an architecture that can be used to extend MPLS networks to integrate access, aggregation and core networks into a single MPLS domain. Seamless MPLS is not a new protocol suite. It is based on existing protocols (like BGP and LDP) and therefore provides a logical and easy evolution path. Seamless MPLS provides a robust framework which enables seamless, scalable and resilient end-to-end MPLS services.


First, Seamless MPLS makes deploying services faster and more flexible. Existing MPLS networks are typically implemented and operated as separate networks (i.e. Core, aggregation or access). MPLS Services on the other may have end points within a metro network or need to cross from one metro network to the other. Creating Services across metro networks requires provisioning of multiple segments and end points which requires co-ordination at the network boundaries. Seamless MPLS removes domain boundaries and extends the topology into a single MPLS domain, so service can be deployed faster and between any two points (Seamless) in the end-to-end MPLS network. Next, it provides the kind of scale today’s networks need. Evolving to end-to-end MPLS networks results in networks with a significantly larger number of MPLS nodes. In particular, access nodes (Cell Site Routers, DSLAMs, Ethernet CPE) make up the largest number of nodes. Additionally these access nodes may not have the same functionality as aggregation or core MPLS nodes. In order to obtain a highly scalable architecture Seamless MPLS helps scale the end-to-end network to more than 100,000 MPLS devices, recognizing that access nodes have limited capabilities and therefore keeps access node functionality as simple as possible. And finally, it enables a highly resilient and manageable end-to-end network. Seamless MPLS supports end-to-end fault detection, fast protection and end-to-end operations, administration and maintenance (OAM) functions. This end-to-end visibility and recovery from faults provides reduced service downtime which is critical for end users. Several large service providers have already implemented Seamless MPLS within their networks. Many operators are now evaluating Seamless MPLS for mobile backhaul architectures and for evolution to converged (intra-AS or inter-AS) MPLS architectures. The technical considerations for implementing a Seamless MPLS network may include evaluating existing network equipment for seamless MPLS features support, as well as interoperability testing across multi-vendor equipment within the metro and core regions. Seamless MPLS will continue to play a crucial role in transforming the metro network to meet the increasing demand for video, mobile broadband and Cloud services.


Read the Seamless MPLS paper 'Evolving to "End-To-End MPLS" Architectures' for additional details. This paper reviews the motivation, architecture and building blocks required to implement a Seamless MPLS network. In addition it describes alternate interim options for deploying end-to-end MPLS networks. Alcatel-Lucent’s IP Routing solution, offers a complete toolkit to implement “end-to-end MPLS” networks. To contact the author or request additional information, please send an email to

Anthony Peres

About Anthony Peres

Anthony Peres has close to 25 years of experience in the IT/Telecommunications industry, with experience in IP/MPLS Network Design & Consulting, Product Management, Business Development, Solution Consulting and Product Marketing in various roles during his tenures at Wipro India, Newbridge Networks Canada and Alcatel-Lucent Canada. Anthony focuses on Alcatel-Lucent’s IP/MPLS products (Metro Aggregation, IP Edge and IP Core Routing) and service provider solutions in the residential, business and mobile segments. Anthony has completed his engineering studies in Mumbai, India and has an MBA from the University of Ottawa, Canada.

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