RFC 2340 (rfc2340) - Page 2 of 14

Nortel's Virtual Network Switching (VNS) Overview

RFC 2340        Nortel's Virtual Network Switching (VNS)        May 1998


      8.1   Equal Cost Multipaths ..................................  10
      8.2   Trunk Load Spreading ...................................  10
   9       Class of Service ........................................  11
   10      VNS Migration Strategies ................................  11
   11      Summary .................................................  11
   12      Security Considerations .................................  12
   13      Acknowledgments .........................................  12
   14      Authors' Addresses ......................................  13
   15      Full Copyright Statement ................................  14

1. Introduction

   There are several key problem areas with today's wide area backbone
   networks that carry LAN traffic: scalability, service
   differentiation, redundancy, administration, and traffic containment.

   First, scalability is becoming a major concern because of the rapid
   growth in bandwidth demand and geographical reach. As the size of the
   WAN network grows traditional point-to-point and NBMA topologies or
   network models lose their performance.

   Second, the need to provide several Classes of Service (CoS) has
   never been greater. The days of a single "best effort" service are
   over and service providers demand ways to differentiate the quality
   of the service offered to their clients based on several policies.

   Third, the WAN is often carrying mission-critical traffic and loss of
   service is not acceptable. So far, path redundancy has been addressed
   inefficiently by requiring additional links or VCs.

   Fourth, network operators demand easy and simplified network
   administration. Large NBMA topologies require extensive PVC
   provisioning until SVC  deployment becomes more ubiquitous. For
   Point-to-point models, IP address space may be used inefficiently and
   non-trivial network schemas are required to contain reserved address
   space.

   Finally, proper segregation of traffic is becoming a must. This
   requirement is being addressed today by adding leased lines or VCs
   used to separate traffic flows based on regions or interest or
   protocol.

   Nortel's Virtual Network Switching (VNS) is a technology that
   provides efficient solutions to these challenges.







Jamoussi, et. al.            Informational