Patent ID: 8386692

Claim:
A method to communicate between nodes in a server apparatus that includes a plurality of input/output devices, a plurality of processor groups each having a plurality of processors, a plurality of node controllers connected to the plurality of processor groups, and a cross bar provided between the plurality of input/output devices and the plurality of node controllers, and transmits and receives a message between the plurality of input/output devices and the plurality of processors via the cross bar, the method comprising: associating each of the plurality of input/output devices with each of the plurality of node controllers; transmitting a message from an input/output device to a cross bar designating a first node controller as a fixed destination, the first node controller being a node controller associated with the input/output device, the message including a fixed-length destination ID that is identification information assigned to an input/output device or a node controller that is to receive the message, and internal information to specify a target; transmitting the message from the cross bar to the first node controller; generating information indicating the target based on the internal information of the received message at the first node controller; adding the generated information to the message; transmitting the message added with the generated information from the first node controller to the cross bar designating a second node controller as a destination, the second node controller being a node controller associated with an input/output device that is the target or a node controller connected to a processor group having a processor that is the target; restoring the message by deleting the generated information from the message added with the generated information at the cross bar; and transmitting the restored message to the second node controller.