Large-scale layer 2 metropolitan area network

Abstract

A system and method permits the creation of very-large metropolitan area networks (MANs) using Layer 2 (L2) switching technology. Different groups of L2 switches are logically organized into Islands. Connected to each Island are a plurality of customers sites, and an interconnect fabric couples the Islands together. The Islands cooperate to provide a Virtual Ethernet Connection (VEC) to each set of customer sites being coupled together. Customers identify their traffic that corresponds to a VEC by labeling or tagging it with a Customer-Equipment VLAN Identifier (CE-VLAN ID). Within each Island, the CE-VLAN ID specified by the customer's traffic (and hence the corresponding VEC) is mapped to a unique MAN Provider-Equipment VLAN ID (PE-VLAN ID). To prevent the formation of loops, the Islands run the Inter-MAN Control Protocol (IMCP), which represents a modified version of the Multiple Spanning Tree Protocol (MSTP).

Description

Large-Scale Layer 2 Metropolitan Area Network technical field The present invention relates to computer networks, and more particularly, to large-scale metropolitan area networks. Background technique Many organizations, including businesses, governments, and educational institutions, utilize computer networks so that employees and others can share and exchange information and / or resources. A computer network generally includes entities interconnected by one or more communication media. An entity may consist of any device, such as a computer, that "sources" (ie sends) or "sinks" (ie receives) frames of data over a communication medium. One common type of computer network is a local area network ("LAN"), which generally refers to a private network within a single building or campus. LANs typically employ data communication protocols (LAN standards) such as Ethernet, FDDI or Token Ring, which define the functions performed by the data link and physical layers of the commun...

AI Technical Summary

Problems solved by technology

As a result, building and running MAN can be expensive

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