Northern Telecom Limited

Nortel Networks Corporation

France Caron

Jean M Regnier

Francois Bedard

Francedillaois Bedard

Francis Langlois

Dynamically controlled routing using dynamic management of intra-link

A dynamically controlled routing (DCR) telecommunications network is formed by a plurality of network switching elements, each connected to at least one other by at least one circuit group for carrying calls therebetween, and a network processor connected to the network elements by data links. Each network switching element determines, for each call, a neighboring network element to which it should be routed. It does so by accessing a routing table which contains alternate routes to be attempted if a direct route either does not exist or cannot be used. The routing tables are updated periodically by the network controller. The DCR network functions as a group of nodes interconnected by links and routing takes place on a node-to-node basis. At least one of the nodes is a logical entity which does not necessarily have a direct correspondence to a single physical network element but rather corresponds to a group of at least one physical component which may be a network element, a part of a network element, or a plurality of network elements or parts thereof. Likewise, a link to the virtual node does not necessarily correspond to a circuit group but comprises the set of direct circuit groups connecting to the components of the virtual node. DCR networks employing virtual nodes have increased flexibility. For example, final destinations outside the DCR network can be associated with the virtual node ifs an intermediate destination node, thereby allowing a call to exit the DCR network via any of the components of the virtual node rather than via only one Unique Exit Gateway.

Dynamically controlled routing using virtual nodes

A congestion control system is provided which is an enhancement of the dynamic call routing system taught by Szybicki et al. in U.S. Pat. No. 4,284,852. The congestion control system includes two parts, a restrictive control and an expansive control. The restrictive control uses data collected by the network processor to provide a call gapping recommendation which is automatically updated each cycle (typically 10 seconds). The call gapping recommendation is used to restrict entry of calls to the network. The expansive control system uses a call compression factor to deflect tandem traffic from overloaded nodes. If direct traffic continues to increase, the restrictive control takes over from the expansive control.

Congestion control system for telecommunications

Growing community of inventors

Verdun, Canada

France Caron