Service Chain Packet Path Tracking for Latency and Drop Visibility

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Solution Overview

Problem

Determining packet path visibility, packet drops, and latency measurements in networked computing environments with service chaining is challenging due to complex service chaining requirements, which include sending packets to devices outside the networked computing environment, making it difficult to calculate latencies and identify packet-dropping nodes.

Innovation Solution

Techniques for determining packet paths and latencies involve receiving flow data from leaf switches, using timestamp data to track packet paths and re-entry points, and calculating latencies based on timestamp differences, even when packet headers change.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If service chaining is implemented to send packets to external devices, then network functionality and service capability are improved, but packet path visibility and latency measurement capability deteriorate

Engineering Contradiction:

Improveservice chaining capabilityVSAvoidlatency measurement precision

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system performs preliminary actions by inserting timestamp values into packet headers before packets are sent to external service chain devices. The ingress leaf switch stamps packets with timestamps as they enter the fabric, and the egress leaf switch records timestamps when packets return. This preliminary timing action enables accurate latency calculation despite packets traversing external networks, resolving the measurement precision deterioration caused by service chaining.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary measurement mechanism using timestamp values that mediate between the internal fabric and external service chain devices. These timestamps act as intermediary markers that allow the system to measure latency across packet paths that extend beyond the fabric boundaries, maintaining measurement precision while preserving service chaining adaptability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If service chaining is implemented to send packets to external devices, then network functionality is improved, but packet path visibility deteriorates

Engineering Contradiction:

Improveservice chaining capabilityVSAvoidpacket path visibility

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The system performs preliminary actions by recording the ingress leaf switch identifier and egress leaf switch identifier before and after packet traversal through external service chain devices. This preliminary recording action preserves complete packet path information even when packets leave the fabric, preventing information loss while maintaining service chaining functionality.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces intermediary path tracking mechanisms using leaf switch identifiers that mediate between internal fabric nodes and external service chain devices. These identifiers act as intermediary markers that maintain packet path visibility across fabric boundaries, resolving the information loss problem while preserving service chaining adaptability.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If complex service chaining requirements are implemented, then service capability is improved, but the ability to calculate latencies for specific nodes deteriorates

Engineering Contradiction:

Improveservice chaining capabilityVSAvoidlatency calculation difficulty

Core Design Contradiction:

Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent segments the latency measurement task into distinct components: ingress timestamp recording at the entry point, egress timestamp recording at the exit point, and centralized calculation by the network controller. This segmentation simplifies the measurement process despite complex service chaining, allowing specific node latency calculation by comparing timestamps at different fabric boundaries.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The network controller acts as an intermediary that collects timestamp data from leaf switches and performs centralized latency calculations. This intermediary approach simplifies the detection and measurement process by centralizing the computational complexity, allowing the system to handle complex service chaining requirements while maintaining ease of latency calculation for specific nodes.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12592987B2Path visibility, packet drop, and latency measurement with service chaining data flows

Publication Date: 2026.03.31 CISCO TECHNOLOGY INC

AI summary

Techniques for determining packet path visibility, packet drops, and latency measurements associated with data flows of a networked computing environment are disclosed herein. The techniques may include receiving flow data associated with a data flow of a networked computing environment and determining a packet path associated with the data flow. The packet path may indicate that a first leaf switch is configured to send packets to a service chain device and that a second leaf switch is configured to receive the packets from the service chain device. The techniques may also include receiving timestamp data indicating a first time when the first leaf switch sent a packet to the service chain device and a second time when the second leaf switch received the packet from the service chain device. Based at least in part on the timestamp data, a latency associated with the service chain device may be calculated.