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Welcome to twampy

twampy is a Python implementation of the Two-Way Active Measurement Protocol (TWAMP and TWAMP light) as defined in RFC 5357 and the Simple Two-Way Active Measurement Protocol (STAMP) as defined in RFC 8762.

This tool was developed to validate Nokia SR OS and SR Linux TWAMP/STAMP implementations and provides comprehensive network latency measurement capabilities.

Overview

twampy is a network measurement tool that enables accurate measurement of:

  • Latency - Round-trip delay between network endpoints
  • Jitter - Packet delay variation (calculated per RFC 1889)
  • Packet Loss - Percentage of packets lost in transit

Features

  • ✅ Multiple Operation Modes - Controller, Control Client, Session Sender, Reflector
  • ✅ Dual Stack Support - Both IPv4 and IPv6
  • ✅ QoS Control - DSCP/TOS field configuration
  • ✅ Flexible Packet Sizing - Custom padding, jumbo frames, IMIX traffic
  • ✅ Fragmentation Control - DF (Don't Fragment) flag support
  • ✅ Standards Compliant - Follows RFC 5357, RFC 4656, RFC 1889

Modes of Operation

TWAMP Controller

Combined Control Client and Session Sender that establishes a control connection to a TWAMP server and initiates test sessions.

TWAMP Control Client

Establishes control sessions with TWAMP servers to run TWAMP light test sessions.

TWAMP Test Session Sender (TWAMP light)

Sends test packets directly to a reflector without control session negotiation.

TWAMP light Reflector

Receives test packets and reflects them back to the sender with timestamps.

Protocol Support

  • TWAMP (RFC 5357) - Two-Way Active Measurement Protocol
  • TWAMP light - Simplified variant without control channel
  • STAMP (RFC 8762) - Simple Two-Way Active Measurement Protocol
  • STAMP Extensions (RFC 8972) - Optional extensions including Session Identifier (SSID)
  • Unauthenticated mode - Currently supported mode
  • IPv4 and IPv6 - Full dual-stack support

Use Cases

  • Validate TWAMP/STAMP implementations on network devices (Nokia SR OS, SR Linux)
  • Measure network latency and jitter
  • Test Quality of Service (QoS) configurations
  • Verify network SLAs
  • Troubleshoot network performance issues
  • Generate traffic with specific characteristics

Getting Started

Check out the Installation Guide to get started, then see the Usage Guide for examples.

Limitations

Current Limitations

  • Software timestamping only - No hardware timestamping support (less precise)
  • Unauthenticated mode only - Authenticated/encrypted modes not yet implemented
  • DF flag support - Limited to Linux and Windows (not supported on macOS/FreeBSD)

License

This project is licensed under the BSD-3-Clause license. See LICENSE for details.