MPLS Ping Return Path via ASBR Identity Stack
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional MPLS networks face limitations in pinging remote nodes across multiple autonomous systems, as the identity of the ping initiator is not recognized beyond the originating AS, preventing traditional pings from spanning multiple autonomous systems due to difficulties in propagating intra-AS addresses and lacking return path routing information.
Innovation Solution
A mechanism is implemented where the identity of the originating node and successive nodes are stored in a stack associated with the ping request, allowing the pinged node to use this information for return path routing, enabling the ping response to traverse the same path and maintain the identity of nodes for accurate routing across multiple autonomous systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional ping operations are used in MPLS networks, then reachability detection within a single autonomous system is achieved, but the ping initiator identity cannot be recognized beyond the originating AS, preventing multi-AS reachability detection
Solution Approach 1:
The patent segments the ping operation into distinct phases: intra-AS ping initiation, inter-AS routing using BGP, and return path establishment. By dividing the multi-AS ping problem into manageable segments (local AS ping, AS path traversal, return routing), each handled by appropriate protocols, the system achieves both reliable reachability detection and multi-AS versatility
Solution Approach 2:
The patent introduces BGP as an intermediary protocol that mediates between the MPLS ping operation and multi-AS routing requirements. BGP carries the ping request across autonomous systems and enables return path routing, acting as a bridge that allows ping initiator identity to be recognized and routed correctly across AS boundaries without modifying the core MPLS ping mechanism
2Loss of information
If intra-AS addresses are propagated across autonomous systems, then return path routing information can be obtained, but address space conflicts and routing policy violations occur
Solution Approach 1:
The patent extracts the return path routing information from the ping request/response packets and handles it through BGP routing mechanisms rather than propagating intra-AS addresses directly. The intra-AS address information is taken out of the MPLS ping payload and processed through appropriate inter-AS routing protocols, preventing address space conflicts while preserving return path capability
Solution Approach 2:
The patent changes the parameter representation of routing information by converting intra-AS address references into inter-AS route descriptors that are valid across autonomous system boundaries. This parameter transformation allows return path information to be maintained without the harmful effects of direct intra-AS address propagation, such as address space conflicts and routing policy violations
Data Source
AI summary
A mechanism for ASBRs to identify the originating node, or router, in an LSP conversant autonomous system (AS), such as an MPLS VPN environment, maintains the identity of the originating node and successive nodes in subsequent autonomous systems along the path to the node to be pinged. The identity of the transporting nodes is stored in a stack or other object associated with the ping request (ping), such that the pinged node may employ the stored identity as a set of return path routing information. Successive ASBRs store their identity on the stack, in an ordered manner, along the path to the destination. Upon reaching the destination (ping) node, the destination node employs the identity of the first node on the stack to send the acknowledgment, or ping response. Each successive ASBR, therefore, pops (retrieves) the next node identity from the stack and redirects (sends) the ping response to the retrieved node.