EVPN Local Switching Convergence via Dual MPLS Labels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing Ethernet virtual private network (EVPN) technologies face challenges in optimizing local switching for flexible cross-connects, particularly in achieving fast convergence and reducing the number of MPLS labels required, which is essential for efficient communication in multi-homed environments.
Innovation Solution
A device assigns two MPLS labels to a single flexible cross-connection and establishes an EVPN backup path by exchanging these labels with a peer router, enabling local switching without BGP signaling, thus allowing for fast convergence and reduced label usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional EVPN local switching is used with BGP signaling, then route convergence is achieved, but convergence time is slow and multiple MPLS labels are required
Solution Approach 1:
The patent applies preliminary action by pre-establishing backup EVPN paths and pre-configuring label mappings before failures occur. When a local switching failure is detected, the system can immediately switch to the pre-prepared backup path without waiting for BGP route advertisements, achieving fast convergence while maintaining reliability
Solution Approach 2:
The patent extracts the dependency on BGP signaling for failure notification by implementing local failure detection and direct switching to backup paths. This separation allows the system to achieve convergence independent of BGP route advertisement delays, reducing convergence time while maintaining reliable route switching
2Adaptability or versatility
If multiple MPLS labels are assigned to flexible cross-connections, then routing flexibility is improved, but label complexity and memory requirements increase
Solution Approach 1:
The patent applies universality by making a single MPLS label serve multiple functions: it identifies both the flexible cross-connection and the specific endpoint within that cross-connection. This multi-functional label approach maintains routing flexibility for multiple endpoints while reducing label management complexity compared to using separate labels for each endpoint
Solution Approach 2:
The patent merges the cross-connection identification and endpoint identification into a single MPLS label structure. By combining these functions into one label, the system reduces the number of labels that need to be managed and stored, decreasing device complexity while preserving the ability to route to multiple endpoints through a single flexible cross-connection
Data Source
AI summary
In one embodiment, a device in a network assigns two multi-protocol label switching (MPLS) labels to a single flexible cross-connection maintained by the device for a plurality of endpoint. The device establishes an Ethernet virtual private network (EVPN) backup path to a peer router for the flexible cross-connection in part by exchanging the MPLS labels with the peer router. The device detects a communication failure that resulted from attempting to send a packet between a first one of the endpoints and a second one of the endpoints using local switching on the device and via the flexible cross-connection. The device sends the packet towards the second endpoint using the EVPN backup path to the peer router, after detecting the communication failure and without first using Border Gateway Protocol (BGP) signaling to signal the communication failure to the peer router.