Browse Prior Art Database

Original Publication Date: 2000-Mar-01
Included in the Prior Art Database: 2003-Jun-20

Publishing Venue



New functionality has been added to Fault Service Daemon code of an SP/NT node to provide a mechanism for the node to determine which port of the adjacent TrailBlazer switch chip it is attached to. Non-disruptive service packets are sent to each port of the chip by the node. The packet contains the target port id. When a node receives a packet, it is able to determine the port to which it is attached by the target id the packet contains. Previous software for managing nodes of an SP switch fabric require a logical id to be given to each node from an external source (normally installation). The addition of functionality to support self-discovery of the port of the TrailBlazer switch chip to which this node is attached is combined with a direct mapping of that port id to a logical id. Once the node doing the self-discovery determines its logical id, it can distribute logical ids to the other nodes on the fabric. This removes the need for the logical id to be supplied externally. Software subroutines have been written to perform this self-discovery. The main subroutine can be called during initialization of the management code on a node. The new code builds a TBS_READ_STATUS service packet. This packet is used once for each port of the TrailBlazer Switch Chip. New software builds a destination route for each port of the chip. This route is appended to the front of the service packet. The destination port number is placed in a previously unused field of the service packet. The node will transmit such a service packet addressed to each port, containing the address of the port, to the switch chip. The switch chip will then send the packet out the destination port. If the node receives the packet, it will take its destination id out of the packet, and successfully terminates the algorithm. The READ_STATUS service packet was chosen because it is non-disruptive. Any other service packet renders the entire switch fabric unusable. Sending too many packets to ports that do not read them may block the switch fabric, again rendering it unusable. There are four possibilities for the hardware which is attached to the ports of a switch chip. There will either be a node, a wrap plug, another switch chip, or nothing. The