Virtual LDP Session

A node comprising:

• one or more processors;
• and
• a memory to store instructions executable by the one or more processors, to perform operations comprising:
• detecting receipt of a vInit message from a first node;
• and
• the vInit message comprises a request to establish a vLDP session between a requesting node in a first network segment and a target node in a second network segment, wherein the vinit message comprises an address for the requesting node and an address for the target node;
• extracting a stack of one or more relay labels from the vinit message,
• wherein the one or more relay labels were provided by one or more relay nodes and define a return path from the target node back to the requesting node for messages transmitted over the vLDP session, and
• wherein the one or more relay nodes are located between the requesting node and the target node;
• determining, based on the address for the target node, that the node is the target node;
• and
• transmitting a responsive vinit message to the requesting node, wherein:
• the vinit message received by the target node comprises a session identifier (ID) that identifies the vLDP session;
• the responsive vinit message comprises the session ID;
• and
• the responsive vinit message confirms that the request to establish the vLDP session is accepted;
• after transmitting the responsive vinit message, generating a virtual LDP message (“vLDP message”) destined for the first node, wherein the virtual LDP message comprises a LDP label mapping message destined for the requesting node, wherein the virtual LDP message comprises the stack of one or more relay labels;
• and
• transmitting the virtual LDP message to the first node.

One or more non-transitory computer-readable storage media to store instructions that, when executed by one or more processors of a receiving node, cause the one or more processors to perform operations comprising:

• detecting, by the receiving node, receipt of a virtual Label Distribution Protocol initialization (vinit) message from a first node, wherein the vInit message comprises a request to establish a virtual Label Distribution Protocol (vLDP) session between a requesting node in a first network segment and a target node in a second network segment, wherein the vinit message comprises an address for the requesting node and an address for the target node;
• extracting a stack of one or more relay labels from the vinit message,
• wherein the one or more relay labels were provided by one or more relay nodes and define a return path from the target node back to the requesting node for messages transmitted over the vLDP session, and
• wherein the one or more relay nodes are located between the requesting node and the target node;
• determining, based on the address for the target node, that the receiving node is the target node;
• and
• transmitting a responsive vinit message to the requesting node, wherein:
• the vinit message received by the target node comprises a session identifier (ID) that identifies the vLDP session;
• the responsive vinit message comprises the session ID;
• and
• the responsive vinit message confirms that the request to establish the vLDP session is accepted;
• after transmitting the responsive vinit message, generating a virtual LDP message destined for the first node, wherein the virtual LDP message comprises a LDP label mapping message destined for the requesting node, wherein the virtual LDP message comprises the stack of one or more relay labels;
• and
• transmitting the virtual LDP message to the first node.