Loop Elimination in Communications Networks via Domain Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing network protocols, such as Spanning Tree Protocol (STP) and Per-Virtual Local Area Network Spanning Tree Protocol (PVST), face challenges in large networks due to resource overburden, congestion, and the inability to provide the best or most direct path, especially in geographically large networks with shared spanning tree instances and VLANs.
Innovation Solution
The solution involves establishing physical topology-based domains within the network to restrict Bridge Protocol Data Units (BPDUs) and implementing loop-elimination protocols on a per-domain basis, reducing network convergence times and bandwidth usage by dividing the network into separate physical domains and regulating BPDU distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If STP is applied in a geographically large network to eliminate loops, then loop-free topology is achieved, but network resources are overburdened and congestion occurs due to BPDUs traveling throughout the entire network
Solution Approach 1:
The network is divided into multiple spanning tree instances, each covering a specific geographic or logical portion of the network. BPDUs are confined to their respective spanning tree domains and do not traverse the entire network. This segmentation reduces the burden on network resources while maintaining loop-free topology within each domain.
2Reliability
If STP calculates a spanning tree covering the entire network, then loop elimination is achieved, but BPDUs may expire before reaching distant nodes due to hop limit constraints
Solution Approach 1:
The network is partitioned into multiple smaller spanning tree domains. BPDUs travel only within their designated domain, significantly reducing the number of hops required to reach destination nodes. This prevents BPDU expiration due to hop limits while still achieving loop elimination within each domain.
3Reliability
If a single spanning tree covers the entire network, then loop-free operation is ensured, but provider and customer networks share the same spanning tree instance causing conflicts
Solution Approach 1:
Multiple spanning tree instances are created, allowing provider and customer networks to be assigned to different instances. Each spanning tree operates independently with its own set of BPDUs, enabling logical isolation between providers and customers while maintaining loop-free operation within each instance.
4Reliability
If STP deactivates ports with higher path cost, then loops are prevented, but the best or most direct path may not be utilized
Solution Approach 1:
By dividing the network into multiple spanning tree domains, the patent enables more direct paths within each domain while maintaining loop prevention. Traffic can flow through optimized paths within a domain without being forced to take suboptimal routes around the entire network, improving transmission speed while preserving loop-free operation.
Data Source
AI summary
Loop-elimination in a network is provided by establishing a physical topology based domain within the network and restricting protocol data units that are received within the physical topology based domain from being consumed at a network node outside of the physical topology based domain, wherein the protocol data units include loop-elimination information. The loop-elimination technique may also include identifying a logical based domain that exists within the network and then restricting protocol data units that are received within the physical topology based domain and the logical based domain from being consumed outside of the physical topology based domain and the logical based domain.