An interconnection network for providing data transfer between a plurality of nodes of an integrated circuit comprises a number of endpoints for exchanging data with respective nodes of the integrated circuit, a primary network to route a primary payload from a source endpoint to a destination endpoint; and a redundant network to route, to the destination endpoint, a redundant payload comprising a first check code calculated based on at least a portion of the primary payload, the first check code having fewer bits than said at least a portion of the primary payload. The destination endpoint comprises error checking circuitry to perform an error checking operation to calculate a second check code based on the primary payload received via the primary network, and verify integrity of the primary payload based on a comparison of the second check code with the first check code received via the redundant network.