Specification of Test Case Structure for Protocol Testing Automation

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.¶

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.¶

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."¶

This Internet-Draft will expire on 5 January 2026.¶

Copyright Notice

Copyright (c) 2025 IETF Trust and the persons identified as the document authors. All rights reserved.¶

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.¶

Table of Contents

1. Introduction

Test cases have long served as a foundational element in evaluating network protocol implementations. Over the past several decades, informal conventions and community practices have emerged for describing and executing such tests. Despite this evolution, a formal, standardized specification for test case structure remains absent. As a result, test cases are often documented in ad hoc formats, leading to ambiguities in interpretation, inconsistent implementations, and challenges in sharing or reusing test artifacts across different environments.¶

The rise of automated network testing frameworks and protocol-agnostic validation systems has significantly raised the bar for test case clarity, precision, and interoperability. In these automated systems, even minor ambiguities in test definition can result in incorrect behavior, reduced repeatability, and difficulty in diagnosing failures. A standardized test case structure is therefore critical not only to eliminate misinterpretation during implementation but also to facilitate test intent preservation, enable reproducible testing, and support automated validation pipelines.¶

This document proposes a unified, machine-readable specification for network protocol test cases. The goal is to bridge the gap between legacy testing practices and modern automation needs by providing a clear, extensible, and interoperable schema for describing test logic, environment, parameters, and evaluation criteria. By aligning the test case definition with automation requirements, this specification lays the groundwork for improved consistency in protocol testing and advances in test automation research.¶

2. Definition and Acronyms

DUT: Device Under Test¶

CLI: Command Line Interface¶

Tester: A network device for protocol conformance and performance testing. It can generate specific network traffic or emulate particular network devices to facilitate the execution of test cases.¶

3. Test Case Classification

Protocol test cases can be broadly classified into the following categories. Each category serves a distinct validation goal and may require specialized tools or methodologies:¶

• Conformance Testing: Validates whether a protocol implementation adheres strictly to the normative requirements defined in the protocol specification. Conformance test suites are typically designed with exhaustive coverage and are essential for standard compliance.¶

• Functional Testing: Verifies that the implementation performs its intended functions correctly under both normal and edge-case conditions. Unlike conformance testing, which focuses on specification adherence, functional testing emphasizes operational behavior in representative scenarios, such as route convergence, state transitions, and control plane interactions.¶

• Performance and Scalability Testing: Evaluates key performance metrics such as throughput, latency, jitter, packet loss, and control plane convergence time. Tests in this category are often based on established benchmarking methodologies (e.g., [RFC2544], [RFC2889], [RFC5180]) and may also assess scalability under stress conditions, such as large-scale route distribution or high-volume traffic forwarding.¶

• Interoperability Testing: Ensures that multiple implementations of the same protocol (often from different vendors) can interoperate correctly. This type of testing focuses on real-world integration scenarios and is critical for multi-vendor environments. Interoperability testing is commonly performed in plugfests or consortium-organized test events.¶

• Robustness Testing: Assesses the implementation's resilience against malformed, unexpected, or adversarial inputs. These tests may include protocol fuzzing, boundary condition violations, or replayed traffic anomalies. While related to security testing, robustness testing typically focuses on fault tolerance and graceful failure handling rather than exploit prevention.¶

4. Test Case Specification

Each test case MUST consist of the following components:¶

5. Application Scenarios

6. Usage Example

The following is a test case example for the OSPF HelloInterval mismatch scenario.¶

test-id: TC-OSPF-HI-001
title: OSPFv2 HelloInterval Mismatch Negative Test
purpose: >
  To verify that the DUT correctly rejects OSPF neighbor formation
  when receiving Hello packets with a mismatched HelloInterval value.
category:
  - Conformance Testing
protocol:
  - OSPFv2
references:
  - RFC2328 Section A.3.2

topology:
  nodes:
    - name: TesterA
      role: tester
      interfaces:
        - name: PortTesterA_1
          ip: 192.0.2.100/24
          connected_to: DeviceA:PortDeviceA_1
    - name: DeviceA
      role: DUT
      interfaces:
        - name: PortDeviceA_1
          ip: 192.0.2.1/24
          connected_to: TesterA:PortTesterA_1
  links:
    - node1: TesterA:PortTesterA_1
      node2: DeviceA:PortDeviceA_1

test-setup:
  DUT-initial-config:
    - Configure interface PortDeviceA_1 with IP 192.0.2.1/24
    - Enable OSPFv2 on PortDeviceA_1
    - Set HelloInterval = 10 seconds on PortDeviceA_1
  tester-initial-config:
    - Configure interface PortTesterA_1 with IP 192.0.2.100/24
    - Enable OSPFv2 on PortTesterA_1
    - Set HelloInterval = 5 seconds on PortTesterA_1

parameters:
  OSPF.HelloInterval.DUT: 10s
  OSPF.HelloInterval.Tester: 5s
  Network.Mask: 255.255.255.0
  OSPF.Network.Type: Broadcast
  OSPF.Area: 0.0.0.0

procedure:
  - step: 1
    action: >
      Initialize both DUT and Tester with the respective interface
      IPs and enable OSPF.
    evaluation: CLI log and interface status verification
    expected: >
      Interfaces are up and OSPF is enabled with configured
      HelloIntervals.
  - step: 2
    action: >
      Verify OSPF neighbor state between DUT and Tester.
    evaluation: >
      OSPF neighbor state via CLI and OSPF adjacency state table.
    expected: >
      No OSPF adjacency is formed. DUT interface remains in Down or
      Init state.

evaluation-criteria:
  functional: >
    DUT must reject Hello packets with mismatched HelloInterval and
    not form adjacency.
  performance: null
  pass-fail: >
    PASS if no neighbor relationship is formed; FAIL if OSPF
    adjacency state reaches 2-Way or Full.
  logging:
    - OSPF neighbor state transitions on DUT
    - Packet capture if applicable
    - Interface and OSPF logs on DUT and Tester

7. Security Considerations

This document defines a test case specification format and does not introduce new protocols or alter protocol behaviors. However, the following considerations apply:¶

1. Test Artifacts Sensitivity: Test configurations and captured traffic may include sensitive information (e.g., IP addresses, authentication exchanges). Proper data sanitization and access control should be enforced during storage and sharing.¶

2. Fuzzing and Adversarial Inputs: Some robustness test cases may involve malformed or adversarial inputs. Care must be taken to ensure such inputs do not propagate beyond the test environment or affect uninvolved systems.¶

8. IANA Considerations

This document has no IANA actions.¶

9. Informative References

[RFC2544]

Bradner, S. and J. McQuaid, "Benchmarking Methodology for Network Interconnect Devices", RFC 2544, DOI 10.17487/RFC2544, March 1999, <https://www.rfc-editor.org/rfc/rfc2544>.

[RFC2889]

Mandeville, R. and J. Perser, "Benchmarking Methodology for LAN Switching Devices", RFC 2889, DOI 10.17487/RFC2889, August 2000, <https://www.rfc-editor.org/rfc/rfc2889>.

[RFC5180]

Popoviciu, C., Hamza, A., Van de Velde, G., and D. Dugatkin, "IPv6 Benchmarking Methodology for Network Interconnect Devices", RFC 5180, DOI 10.17487/RFC5180, May 2008, <https://www.rfc-editor.org/rfc/rfc5180>.

Acknowledgments

This work is supported by the National Key R&D Program of China.¶

Contributors

Zhen Li
Beijing Xinertel Technology Co., Ltd.
Email: lizhen_fz@xinertel.com¶

Zhanyou Li
Beijing Xinertel Technology Co., Ltd.
Email: lizy@xinertel.com¶

Authors' Addresses