End-to-end path delay measurement in SR networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for measuring end-to-end path delays in Segment-Routing (SR) networks are inefficient due to exponential growth in the number of delay measurements required, making it impractical to detect and correct delays within sub-second intervals, especially when dealing with multiple Equal-Cost Multi-Path (ECMP) sections, which can take minutes to measure, violating Service Level Agreements (SLAs) for critical applications.
Innovation Solution
The proposed method determines end-to-end path delay measurements by identifying unique sets of ECMP sections and measuring delays using probe packets, reducing the number of paths to be measured linearly with the number of ECMP sections, allowing for scalable and frequent calculation of delay metrics, eliminating the need for stateful transit nodes and additional protocol extensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional methods measure delay for all end-to-end paths in SR networks, then measurement precision is improved, but the time required increases exponentially, making it impossible to meet sub-second SLA requirements
Solution Approach 1:
The patent segments the network path into ECMP sections and measures delay at each section independently using probe packets. Instead of measuring all end-to-end paths simultaneously, the method divides the measurement task into smaller atomic sections, where each section's delay is measured separately and then aggregated to derive end-to-end delay metrics.
Solution Approach 2:
The patent measures delay for a selected subset of paths through ECMP sections rather than all possible end-to-end paths. By measuring delays for representative paths through each ECMP section and using mathematical aggregation, the method obtains sufficient end-to-end delay information without the exponential measurement overhead of conventional approaches.
2Adaptability or versatility
If the number of ECMP sections increases, then network versatility and routing options improve, but the number of delay measurements required grows exponentially, violating SLA response time requirements
Solution Approach 1:
The patent segments the routing measurement problem into independent ECMP sections. Each section is measured separately with a linear number of probe packets, regardless of the total number of end-to-end paths. This segmentation allows the system to handle increased routing versatility without exponential measurement overhead.
Solution Approach 2:
The patent changes the measurement dimension from end-to-end paths to intermediate ECMP sections. Instead of measuring along the full end-to-end path dimension, the method measures at intermediate section dimensions and aggregates results, reducing the measurement complexity from exponential to linear with respect to the number of ECMP sections.
3Reliability
If conventional methods are used to detect and correct delay violations, then SLA compliance can be ensured, but the detection time exceeds sub-second intervals, making real-time correction impossible
Solution Approach 1:
The patent performs preliminary delay measurements at each ECMP section using probe packets before traffic actually flows through the network. These preliminary section-level measurements are aggregated to predict end-to-end delay, enabling early detection of potential SLA violations before they affect actual traffic, allowing sub-second correction responses.
Solution Approach 2:
The patent implements continuous delay measurement at each ECMP section by continuously sending probe packets through the network sections. This continuous measurement approach provides real-time delay information that can be aggregated and used for immediate SLA compliance verification and correction, unlike periodic end-to-end measurements.
Data Source
AI summary
Techniques are provided for determining end-to-end path delay measurements. In one embodiment, a method includes identifying equal-cost multi-path (ECMP) sections comprising at least two different ECMP paths in a network comprising a plurality of nodes. In response to receiving a request to determine a delay measurement for end-to-end paths from an ingress node to an egress node through the network, the method includes determining sets of ECMP sections that are between the ingress node and the egress node and determining a plurality of paths through each set of ECMP sections. The method includes measuring delay for each of the plurality of paths using probe packets and determining delay measurements for all end-to-end paths. The delay measurements for end-to-end paths include a first subset including measured delays from the probe packets and a second subset calculated using combinations of measured delays.