Stitching multi-domain LSPs in hierarchical SDN architecture

A method to support establishing an end-to-end tunnel for a virtual network (VN) extending across multiple domains using a first network controller element managing a first domain, comprising:

• receiving a request from a second network controller element managing the first network controller element for an inter-domain locally-learned tunnel identifier (LLTI);
• sending, to an ingress network element of the first domain, an instruction to generate the inter-domain LLTI in accordance with the request;
• receiving, from the ingress network element, the inter-domain LLTI in accordance with the instruction;
• and
• sending, to the second network controller element, the inter-domain LLTI so that the second network controller element is able to provide the inter-domain LLTI to an egress network element of a second domain upstream of the first domain to permit data packets to be propagated between the first domain and the second domain.

An ingress network element in a downstream domain utilizing an end-to-end tunnel for a virtual network (VN) extending across multiple domains, comprising:

• a receiver configured to receive:
• an intra-domain locally-learned tunnel identifier (LLTI) from a first network controller element managing the downstream domain, wherein the intra-domain LLTI was generated by an egress network element in the downstream domain;
• and
• a data packet from an upstream egress network element in an upstream domain;
• and
• a transmitter operably coupled to the receiver, wherein the transmitter is configured to transmit the data packet toward the egress network element in the downstream domain using the intra-domain LLTI.

An egress network element in an upstream domain utilizing an end-to-end tunnel for a virtual network (VN) extending across multiple domains, comprising:

• a receiver configured to receive:
• an inter-domain locally-learned tunnel identifier (LLTI) from a first network controller element managing the upstream domain, wherein the inter-domain LLTI was generated by an ingress network element in a downstream domain;
• and
• a data packet from an intermediary network element in the upstream domain;
• and
• a transmitter operably coupled to the receiver, wherein the transmitter is configured to transmit the data packet to the ingress network element in the downstream domain using the inter-domain LLTI.

A method of establishing an end-to-end tunnel for a virtual network (VN) extending across multiple domains using a first network controller element, comprising:

• receiving a request from a customer network controller (CNC) to establish the end-to-end tunnel for the VN extending across the multiple domains;
• sending an instruction to a second network controller element managing a downstream domain to obtain an intra-domain LLTI and an inter-domain LLTI;
• receiving the inter-domain LLTI from the second network controller element;
• sending the inter-domain LLTI to a third network element managing an upstream domain, wherein the inter-domain LLTI corresponds to an inter-domain link extending between an egress network element of the upstream domain and an ingress network element of the downstream domain to permit data packets to be propagated between the egress network element of the upstream domain and the ingress network element of the downstream domain.