Service Function Forwarder Probe Validation for SFC Reliability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional service function and service function forwarder modules in software-defined networks and network function virtualization environments lack the ability to diagnose and prevent incorrect service function type invocations between service function chains, leading to potential security breaches and failures.

Innovation Solution

Implementing a service function forwarder that performs automatic validation of service function types by initiating a probe, such as a modified-traceroute packet, to query and validate the function type of service function modules, using a comparison table to verify the reported function type against expected types, and dropping packets if validation fails to prevent security breaches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If automatic validation of service function types is implemented using probes and comparison tables, then security and reliability of service function chains are improved, but device complexity and processing overhead increase

Engineering Contradiction:
Improveservice function chain reliabilityVSAvoidservice function forwarder complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system performs validation actions in advance by initiating probes to query service function modules and comparing reported function types against expected types stored in comparison tables. This preliminary validation prevents incorrect function invocations before they can cause security breaches or failures, thereby improving reliability while managing complexity through proactive rather than reactive validation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The validation mechanism implements feedback by having the service function forwarder initiate probes to query service function modules, receive their responses, compare the reported function types against expected types, and use this feedback information to determine whether to forward packets. This closed-loop feedback system ensures reliability by continuously verifying function types while maintaining manageable complexity through automated comparison logic.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If probe-based validation is performed for each service function module, then measurement precision of function type verification is improved, but loss of time and processing delay increase

Engineering Contradiction:
Improvefunction type verification accuracyVSAvoidvalidation processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system applies partial action by performing validation selectively - initiating probes to query service function modules and comparing reported function types against expected types only when necessary for packet forwarding decisions. This approach achieves sufficient measurement precision for security validation while avoiding excessive validation of every single function type in all circumstances, thereby reducing time loss and processing delays.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The validation mechanism uses copying by storing expected service function types in comparison tables that can be referenced multiple times. Instead of repeatedly querying service function modules for the same function type information, the system copies the expected types into accessible tables, enabling fast comparisons that maintain measurement precision while significantly reducing validation processing time.

Inventive Principle:
Principle #26Copying

Data Source

PatentEP3482532B1Automatic service function validation in a virtual network environment
Publication Date: 2020.03.18 CISCO TECHNOLOGY INC
  • EP3482532B1 patent drawingFigure 1
  • EP3482532B1 patent drawingFigure 2A
  • EP3482532B1 patent drawingFigure 2B

AI summary

Systems, methods, and computer-readable media for improving the reliability of service function (SF) application in a service function chain (SFC) are provided. In some aspects, the subject technology facilitates automatic service function type validation by a service function forwarder (SFF), for example, by using a probe configured to query a function type of a SF module associated with the validating SFF.