Integrating switching and facility networks using ATM
First Claim
1. A network comprising a plurality of switches interconnected by means of β
- links and edge nodes that connect to at least some of said switches via α
links and also connect to apparatus outside said network, and where datagrams are launched onto said network by said edge nodes with a virtual path identifier, VPI, that is specified by said edge node and an edge node destination, the improvement comprising;
said switches route said datagrams according to the dictates of said virtual path identifier, anda first edge node of said edge nodes that is coupled to a first switch of said switches, when launching a datagram to a second edge node of said edge nodes, employs a first VPI; and
a third edge node of said edge nodes that is coupled to a second switch of said switches that is different from said first switch, when launching datagram to said second edge node of said edge nodes, employs said first VPI.
1 Assignment
0 Petitions
Accused Products
Abstract
An efficient approach and corresponding apparatus for selecting virtual paths in a network for routing datagrams achieves effective sharing of capacity without adversely affecting call setup latency. Edge nodes of the network assign calls to virtual paths based on the destination of the call and the current load status of each of a relatively small number of paths. Each call is assigned a VPI (Virtual Path Identifier) corresponding to the path chosen and a VCI (Virtual Circuit Identifier) corresponding to the identity of the call at that edge node. The ATM backbone nodes route calls based solely on the VPI. Capacity management and load balancing is achieved by each edge node keeping track of the load on each access link from its edge node to the rest of the network and of the congestion status of the various links in the network. In one embodiment, the edge node periodically sends information about its usage of the network to a "central fabric network interface" which combines information from all edge nodes, evaluates congestion status for the network links, and forwards that information back to the edge nodes.
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Citations
30 Claims
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1. A network comprising a plurality of switches interconnected by means of β
- links and edge nodes that connect to at least some of said switches via α
links and also connect to apparatus outside said network, and where datagrams are launched onto said network by said edge nodes with a virtual path identifier, VPI, that is specified by said edge node and an edge node destination, the improvement comprising;said switches route said datagrams according to the dictates of said virtual path identifier, and a first edge node of said edge nodes that is coupled to a first switch of said switches, when launching a datagram to a second edge node of said edge nodes, employs a first VPI; and a third edge node of said edge nodes that is coupled to a second switch of said switches that is different from said first switch, when launching datagram to said second edge node of said edge nodes, employs said first VPI. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
- links and edge nodes that connect to at least some of said switches via α
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21. In a network arrangement comprising switches interconnected by links, and edge nodes that are coupled to at least some of said switches, where said switches route datagrams via said links from a source edge node to a destination edge node, a method of setting up a virtual path from said source edge node to said destination edge node comprising:
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the source edge node maintaining information about a congestion status of said links, based on said congestion status information, the source edge node selecting said virtual path for datagrams to be launched by said source edge node from a set of virtual paths that home onto the destination edge node. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30)
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Specification