CRP Routing Table Segmentation for SDN Controller Route Isolation
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Solution Overview
Problem
In current SDN architectures, when a controller uses routing protocols like BGP or PCEP to advertise routes to forwarding devices, these routes are processed similarly to common routes, leading to preferential selection issues that affect related applications.
Innovation Solution
The implementation of a Control Routing Protocol (CRP) that allows the controller to advertise routes directly to forwarding devices, using a separate CRP routing table to store these routes, thereby avoiding interference with common routing protocols.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the controller uses BGP protocol to advertise routes to the forwarding device, then the routing information can be exchanged between autonomous systems, but the controller's advertised routes are stored in the same BGP RIB as common BGP routes, causing preferential selection issues that affect related applications
Solution Approach 1:
The patent segments the routing information base into separate components: a common BGP RIB for storing routes advertised by forwarding devices and a controller RIB for storing routes advertised by the controller. This segmentation prevents interference between controller routes and common BGP routes, allowing independent route selection policies for each type while maintaining overall system reliability.
Solution Approach 2:
The patent introduces an intermediary mechanism (separate RIB structure and route selection module) that mediates between controller-advertised routes and common BGP routes. The route selection module independently selects routes from the controller RIB and common BGP RIB, preventing direct interference and allowing flexible routing policy implementation.
2Loss of information
If the controller advertises routes using existing routing protocols like PCEP, then routing information can be synchronized, but the same problem occurs where controller routes interfere with common routing protocol applications
Solution Approach 1:
The patent segments the routing table management into distinct components: separate RIB structures for different route types and independent route selection processes. This segmentation simplifies management by allowing each route type to be handled independently while maintaining complete routing information synchronization.
Solution Approach 2:
The patent extracts controller-advertised routes from the common routing protocol processing flow and places them in a separate controller RIB. This extraction eliminates interference with common routing protocol applications while maintaining independent route synchronization and management capabilities.
3Extent of automation
If controller routes are preferentially selected in the same BGP RIB, then the controller can control network traffic, but related applications of common BGP routes are affected
Solution Approach 1:
The patent segments the route selection process into independent modules: one for selecting controller routes from the controller RIB and another for selecting common BGP routes from the common BGP RIB. This segmentation allows automated traffic control based on controller policies while ensuring that common BGP route applications are not adversely affected, as each selection process operates independently.
Solution Approach 2:
The patent introduces an intermediary route selection module that acts as a mediator between controller traffic control requirements and common BGP route applications. This module independently evaluates and selects routes from both RIBs, enabling automated control while protecting the reliability of related applications.
Data Source
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AI summary
This application provides an information synchronization method. The method includes: sending, by a controller, a first message to a network device, where the first message carries CRP routing entry information, and is used to advertise a CRP route, and the first message includes first identification information; and after receiving the first message, storing, by a forwarding device, the CRP routing entry information into a CRP routing table of the network device as indicated by the first identification information. In the technical solutions of this application, because a route advertised by the controller and a route advertised by using a routing protocol between forwarding devices are stored in different routing tables, a related application of the route advertised by using the routing protocol between the forwarding devices is not affected.