Patent ID: 7573885
Filing Date: 2009-08-11
Classification: H04L

Abstract:
1. A computer-implemented method for alternative routing of a connection between a source node and a destination node in a PNNI (Private Network-to-Network Interface) hierarchical network, the method comprising responding to a failed connection between said nodes due to a sole-access element of a network structure as seen by the source node, where a said sole-access element is an element which provides sole access to the destination node in said network structure, by: examining possible routes closest to the destination node; using switch control logic to select at least one non-sole-access element of a particular route used by the failed connection in said network structure; using control logic for identifying an alternative route for the failed connection in said network structure which utilizes said at least one non-sole-access element; using the control logic for using the alternative route for establishment of the failed connection between said source and destination nodes; checking whether said alternative route satisfies a set of predefined connection constraints, wherein said alternative route is used for establishment of the connection only if said constraints are satisfied, wherein said at least one non-sole-access element is a link of said network structure, wherein the step of selecting comprises selecting from the set of all non-sole-access elements used by said failed connection which are outside the PNNI peer group of the source node the link which is closest to a predetermined one of the source and destination nodes, and further comprising: