The Trend Towards IP


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:

  • IP has become the lingua franca of networking ”other protocols, such as Novell's IPX, will continue to exist, but the global protocol will almost certainly be IP version 4, possibly moving to IP version 6.

  • End-user devices, such as mobile phones, PDAs, and TV set-top boxes, have become IP-capable, so end-to-end IP (from the user to the core ) will become more important.

  • Existing layer 2 devices do not easily support massive (scalable) deployment of layer 3 protocols such as is increasingly needed for services like IP VPNs.

  • The need for specialized layer 2 maintenance skills is reduced.

  • A single layer 3 control plane is easier to manage.

  • Aggregation of IP traffic becomes possible, improving scalability.

  • Different ( guaranteed ) levels of network service can be sold to customers.

  • Management system object models can become more generic.

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:

  • MPLS allows traffic engineering ( putting the traffic where the bandwidth is).

  • MPLS integrates IP QoS with layer 2 QoS.

  • Many vendors are providing MPLS capability in their devices ”for example, Cisco, Juniper, Nortel Networks, and Marconi.

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).



Network Management, MIBs and MPLS
Network Management, MIBs and MPLS: Principles, Design and Implementation
ISBN: 0131011138
EAN: 2147483647
Year: 2003
Pages: 150

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