Patent ID: 7082140

Claim:
A method for establishing a multi-protocol label switched (“MPLS”) path for forwarding a packet formatted in accordance with MPLS, including a label stack, through a communication network including a first label switched domain and a second label switched domain interconnected by a non-label switched domain, the method comprising: establishing a tunnel across the non-label switched domain which connects the first label switched domain and the second label switched domain; encapsulating the packet and label stack by appending a non-MPLS protocol header to the packet and label stack, thereby forming an encapsulated packet; setting an identifier in the non-MPLS protocol header to indicate that the label stack is in the encapsulated packet; forwarding the encapsulated packet through the tunnel; receiving the encapsulated packet at the second label switched domain; and de-encapsulating the encapsulated packet by removing the non-MPLS protocol header, whereby label stack information is preserved.