Hierarchical PCE SDN Control for Multi-Domain Tunnel Routing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Path Computation Element (PCE) controllers in networks often lack a complete topology view when creating tunnels or paths across multiple domains, leading to inefficiencies in routing data.
Innovation Solution
Implementing a hierarchical software-defined network (SDN) control system (HSCS) that allows parent PCE controllers to establish relationships with child PCE controllers, enabling the computation and management of end-to-end tunnels across multiple domains by transmitting requests and replies for path segments and tunnel segments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single PCE controller attempts to compute paths across multiple domains, then path computation can be centralized, but the controller lacks complete topology information and cannot efficiently manage complex multi-domain routing
Solution Approach 1:
The patent divides the network into multiple domains, each managed by a domain PCE controller that has complete topology information for its domain. A home PCE controller manages end-to-end paths across domains by coordinating with domain PCEs, segmenting the path computation function to match the segmented network architecture.
Solution Approach 2:
The home PCE controller acts as an intermediary between the PCC and domain PCEs. It receives path computation requests, determines the home domain, coordinates with relevant domain PCEs to obtain path segments, and assembles the complete end-to-end path, thereby solving the topology information problem without requiring every controller to know every domain's topology.
2Loss of information
If path computation is distributed across multiple domain PCE controllers, then each controller has complete local topology information, but coordinating end-to-end paths across domains becomes complex
Solution Approach 1:
The patent merges the path computation functions by having the home PCE controller coordinate with domain PCEs to assemble complete end-to-end paths. The home PCE combines local topology knowledge with domain-specific topology knowledge from domain PCEs to compute paths that span multiple domains, effectively merging information from multiple sources.
Solution Approach 2:
The patent introduces a new dimension to path computation by separating the home domain concept from the domain of the PCE controller. A PCE controller can be the home PCE for a PCC in one domain while being a domain PCE for a different domain, allowing flexible coordination across domain boundaries without requiring a flat hierarchical structure.
3Ease of operation
If a PCE controller manages multiple domains directly, then control is centralized, but the controller becomes a single point of failure and reduces system scalability
Solution Approach 1:
The patent segments the control function by introducing domain PCEs that manage local domain topology and routing. The home PCE controller manages end-to-end path computation but relies on domain PCEs for domain-specific operations, distributing the control function to eliminate single points of failure and improve scalability.
4Ease of manufacture
If offline path computation is used for traffic engineering, then network planning can be done in advance, but real-time path adjustment for new customers is delayed
Solution Approach 1:
The patent uses preliminary action by pre-computing and caching domain paths within each domain PCE controller. When a path computation request arrives, the home PCE retrieves pre-computed domain paths from domain PCEs and quickly assembles the end-to-end path, combining advance preparation with real-time responsiveness.
Data Source
AI summary
A parent PCE controller comprising a memory comprising instructions executable by a processor and a processor coupled to the memory and configured to execute the instructions. Executing the instructions causes the processor to establish a parent-child relationship with at least a first child PCE controller controlling a first domain and a second child PCE controller controlling a second domain, receive a request to create an E2E tunnel from a source to a destination crossing the first domain and the second domain, compute a shortest path from the source to the destination through the first domain and the second domain, transmit a request message to the first child PCE controller for creating a first tunnel segment of the E2E tunnel through the first domain, and transmit a request message to the second child PCE controller for creating a second tunnel segment of the E2E tunnel through the second domain.