As mentioned earlier, a major trend in networking is the migration towards IP. Enterprise (and SP) networks are generally expected to support native IP cores in the next five to ten years . This is often referred to as the next -generation network. There are many reasons for this migration:
Users will continue to access enterprise networks using a variety of technologies, such as ATM, FR, xDSL, ISDN, and POTS (dial-up), but their layer 2 “encapsulated IP traffic will increasingly be extracted and repackaged as pure IP/MPLS at the network edge. In effect, layer 2 traffic is being pushed out of the core and into the access edge of the network. This is another reason for end-to-end IP: The need for terminating multiple layer 2 technologies begins to disappear. MPLS is a good starting point for this migration because:
Many of the issues relating to traffic engineering, QoS, and handling legacy layer 2 services are highly relevant to enterprises and SP networks. Enterprise networks feature an increasingly rich mixture of traffic types: email, Web, audio/video, VoIP, and so on. Such a range of traffic types may well necessitate techniques such as traffic engineering and bandwidth management rather than just adding more capacity (i.e., overengineering the core). |