Metropolitan Networ on the DSL Access Architecture

Without any doubt, broadband Internet access is one of the most successful services offered by telecom operators today. It gives the operator the potential of offering many new services to residential and business customers, thereby introducing new revenue streams. ATM today provides a solid solution for this. At the same time, packet-based aggregation technologies - especially Gigabit Ethernet - are becoming popular for offering connectivity serviccs to business customers. The success of packet-based aggregation technologies is main- ly driven by their lower cost compared ta estab- lished cell-based solutions. This article addresses a number of requirements that must be fulfilled by the access network if it is used to provide multiple services. It will be shown how MPLS and Ethernet can be used in a broadband access architecture. Both meet many of the identified requirements, but still require some standardization before reaching the same maturity as their cell-based counter- part. It will he shown how MPLS technology can be used to seamlessly link cell and packet- centric.networks together. This gives operators the possibility to keep the benefits of their existing cell-based infrastructure and smoothly evolve toward a packet-centric approach when the time is right.