Nortel Networks Corporation

Ewart Tempest

Darek Robert Skalecki

Christopher David Murton

Areef Reza

Paul Fee

Philip Christian

Allen Houston

Resources used by a connection are released when a connection is terminated, for example due to a failure on the network. When the connection is to be redialed, an indication of the released resources is collected and provided to the network element that will perform a redial operation to determine the new path for the connection. This allows the network element to determine the new path using up-to-date information, while not allowing other nodes on the network to know about the recently released resources, so that the head-end node has an initial opportunity to use the recently released resources for the redialed connection. Subsequently any unused resources will be advertised on the network for use by other nodes. The head-end network element may be notified of the resources released from termination of the previous connection by causing a termination message to propagate from the tail-end node to the head-end node and collect feedback along the terminating connection path.

Method and apparatus for redialing a connection on a communication network

The present invention relates to data tunnelling and in one embodiment to the tunnelling of IP (Internet Protocol) data across an OSI (Open Systems Interconnect) network. In the preferred embodiment, network elements include both an OSI stack and an IP stack, and a respective directory of OSI addresses and corresponding IP subnets. Each network element generates a routing data packet, conveniently a Link State Packet (LSP), which includes the OSI address and IP subnet(s) associated with that network element. The LSPs are distributed across the network in normal manner. Upon receipt of an LSP from another network element, each network element updates its respective directory in respect of said other network element. Thus, each directory is automatically updated to reflect changes in the network, particularly in respect of IP subnets. This arrangement significantly reduces the need for manual tunnel configuration in the network. In an alternative embodiment, the invention provides dynamic data tunnelling of OSI data over an IP network.

Dynamic data tunnelling

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Ottawa, Canada

Ewart Tempest