Patent ID: 6256292
Filing Date: 2001-07-03
Classification: H04J,H04L,H04Q

Abstract:
A method for transporting a SONET formatted asynchronous transfer mode (ATM) signal on a unidirectional line switched ring comprising the steps of:connecting a plurality of nodes in a ring network provided with a working transmission line associated with said first direction of transmission and a protection transmission line associated with a second direction of transmission, opposite to first direction;detecting at a node an error signal received from a first adjacent node located adjacent to said node and upstream with respect to said first direction;generating a status change request at said node upon receipt of said error signal, and transmitting said status change request on said working and protection transmission lines;restructuring all said nodes of said ring to operate according to a line switched protocol, in one of a working transmission line failure, a node failure, a protection transmission line failure, and a working and protection transmission line failure configurations, upon receipt of said status change request;the step of restructuring includingremodelling said node to assume a switched state,remodelling said first adjacent node to assume a bridged state, andremodelling all remaining nodes to assume a passthrough state; andwherein said node in said switched state performing the operations of receiving an incoming ATM STS-Mc from said protection transmission line;determining the address of a destination node for said incoming ATM STS-Mc;routing said incoming ATM STS-Mc from said protection transmission line onto said working transmission line if said destination node is not said node;extracting said incoming ATM STS-Mc from said protection fiber if said destination node is said node; andinserting an outgoing STS-Mc originating at said node into said working transmission line.