Patent ID: 8675522

Claim:
A computer-implemented method for packet switching in a Shortest Path Bridging (SPB) network, the computer-implemented method comprising: receiving a multicast data packet at a first data switching device, the first data switching device functioning as a first Backbone Edge Bridge within a transport network using Shortest Path Bridging (SPB) protocol, the multicast data packet having a Mac-in-Mac encapsulation header added by a second data switching device, the second data switching device functioning as a second Backbone Edge Bridge within the transport network, the multicast data packet received via the transport network from the second data switching device, the Mac-in-Mac encapsulation header carrying a data Backbone Service Instance Identifier (I-SID) set in a Backbone Media Access Control Destination Address (BMAC-DA) field of the Mac-in-Mac encapsulation header, the data I-SID identifying a multicast data stream corresponding to the multicast data packet, the Mac-in-Mac encapsulation header also carrying a Layer 2 I-SID set in a Backbone Service Instance Tag (I-TAG) field of the Mac-in-Mac encapsulation header, the Layer 2 I-SID identifying a Layer 2 bridging domain corresponding to the multicast data packet, the Layer 2 I-SID carrying a different value as compared to a value of the data I-SID; executing a lookup at the first data switching device, the lookup identifying Layer 2 bridging domain information of an incoming interface of the multicast data packet and Layer 2 bridging domain information of an outgoing interface of the multicast data packet, the incoming interface connecting a sender of the multicast data stream with the second data switching device, the outgoing interface connecting a receiver of the multicast data stream with the first data switching device; removing the Mac-in-Mac encapsulation header; in response to identifying that a Layer 2 bridging domain corresponding to the outgoing interface is different than a Layer 2 bridging domain corresponding to the incoming interface, modifying a Customer Media Access Control (MAC) Source Address carried in a Customer MAC header field of the multicast data packet; and forwarding the multicast data packet on the outgoing interface without the Mac-in-Mac encapsulation header.