Patent ID: 7061870
Filing Date: 2006-06-13
Classification: H04L,H04Q

Abstract:
1. A method of transmitting a loopback cell of a connection established between a source ATM device and a destination ATM device of an ATM network, said loopback cell being returned at one of at least one switching nodes located on the connection route, said loopback cell entering said switching node by an input port of an input adapter, before being switched to an output adapter as would a normal cell of said connection, and being then switched backward to said input adapter and exiting the switching node by said input port of said input adapter instead of an output port of said output adapter as would the normal cell of said connection, said method comprising the steps of; setting a loop control bit in said output adapter by a control point of said switching node if loopback is permitted in said switching node; detecting in said output adapter whether an incoming cell includes a loopback condition, and if so appending to said incoming cell a specific routing label indicating that the incoming cell is a cell to be returned on the connection; and using said routing label by a protocol engine on said output adapter to transmit said cell back to said input adapter, then over said ATM network from said input port of said input_adapter like the normal cell traveling on the connection in the opposite direction.