US 7,394,820 B1
Interworking unit (IWU) for interfacing a plurality of client devices to a multiprotocol label switching (MPLS)
Robert B. Dianda, Leawood, Kans. (US)
Assigned to Sprint Communications Company L.P., Overland Park, Kans. (US)
Filed on Jan. 28, 2004, as Appl. No. 10/766,265.
Int. Cl. H04L 12/56 (2006.01)
U.S. Cl. 370—401 18 Claims
OG exemplary drawing
 
1. An InterWorking Unit (IWU) for interfacing a plurality of client devices to a MultiProtocol Label Switching (MPLS) network, the IWU comprising:
a plurality of IWU edge nodes adapted for exchanging MPLS frames with the plurality of client devices;
an IWU switch node communicating with the plurality of IWU edge nodes and adapted for exchanging the MPLS frames with the MPLS network, with the IWU switch node being configured to receive a MPLS frame from the MPLS network, with the MPLS frame including an inner label and an outer MPLS label, process the outer MPLS label in order to determine one designated IWU edge node of the plurality of IWU edge nodes, with the one designated IWU edge node being designated by the outer MPLS label, and transfer the MPLS frame to only the one designated IWU edge node;
the one designated IWU edge node being configured to transfer the data transported in the MPLS frame to a designated client device that is designated by the inner label of the MPLS frame;
the IWU switch node further configured to receive a second MPLS frame from the MPLS network, with the second MPLS frame including an improper inner label and a proper outer MPLS label, and transfer the second MPLS frame to a second designated IWU edge node that is designated by the proper outer MPLS label; and
the second designated IWU edge node configured to not transfer the data transported in the second MPLS frame to a designated client device that is improperly designated by the improper inner label of the second MPLS frame.