Patent Number: 6,480,501

Title: Process for transporting a cell through a switching structure base on a single stage switch

Abstract: A process for transporting a data cell throughout a switch fabric having a centralized switching structure and a set of distributed, generally remotely located, Switch Core Access Layers (SCAL) permitting the attachment of the protocol adapters. Remotely with respect to the centralized switching structure, the data cell which is received from a telecommunications link is divided into k logical units (LUs) and additional bytes are introduced for permitting the reservation of a bitmap field that will be used for routing through the switch core. Every LU is coded in accordance with the 8B/10B coding process. Within the centralized switching structure, the k coded LUs are deserialized and the cell clock is obtained for each cell in order to reconstitute the data cell. In addition the routing byte reservations are filled with appropriate values (bit map) for the routing process within the switch by means of an access to an entry routing table. When the cell outputs the switching structure, a second access to a routing table permits the replacement of the previous bit map by new values in order to enhance multicast capabilities. The data cell is divided again in a set of k serialized logical units (LUs) in order to prepare a serialization through k links. The LUs are coded as previously to permit the merging of the LUs when different sets of switches operated in parallel are connected in a port expansion mode. Remotely with respect to the switch core, the coded LUs are deserialized and the data cell is reconstituted by means of the deserialization and extraction of the data cell clock transported by the 8B/10B coding process. The newly inserted values of the bit map are then used for enhancing multicasting capabilities.

Inventors: Blanc; Alain (Vence, FR), Abbiate; Jean-Claude (La Guade, FR)

Assignee: International Business Machines Corporation

International Classification: H04L 12/56 (20060101); H04L 012/54 ()

Expiration Date: 11/12/2019