ipyrf 1.4.0

A tiny iperf3-like tool with JSON output (TCP/UDP)

Minimal iperf3-like network throughput tool with JSON output. Supports TCP and UDP, server and client modes.

Features

• TCP and UDP tests

• JSON or human-readable output

• Optional bandwidth capping (TCP/UDP)

• UDP packet loss estimation

• Linux TCP congestion control selection (if available)

Installation

From PyPI (recommended):

python3 -m pip install ipyrf

From source (editable):

python3 -m venv .venv
source .venv/bin/activate
python3 -m pip install -U pip build
python3 -m pip install -e .

Test Utilities (ipyrf.test)

The ipyrf.test module provides test utilities for writing your own tests:

from ipyrf.test import IPyrfBuilder, CheckCriteria

def test_my_network(testdirectory):
    builder = IPyrfBuilder(testdirectory)
    port = 12345

    server = builder.build()
    client = builder.build()

    server.run_tcp_server("127.0.0.1", port)
    client.run_tcp_client("127.0.0.1", port, duration=2)

    # Check with custom criteria
    builder.check(
        (server, client),
        timeout=5,
        criteria={"min_bps": 1000000}
    )

Available classes and functions:

• IPyrfClient: Run and monitor ipyrf instances

• IPyrfBuilder: Builder pattern for creating test instances

• CheckCriteria: Configurable criteria for evaluating test results

See examples/using_test_utilities.py for more examples.

Running Tests

The project includes a comprehensive test suite using pytest:

# Run all tests
python3 waf --run_tests

Usage

The package installs a console script named ipyrf.

Quick examples

TCP server:

ipyrf tcp server 0.0.0.0 --port 12345

TCP client:

ipyrf tcp client 127.0.0.1 --port 12345 --time 5
ipyrf tcp client 127.0.0.1 --port 12345 --time 5 --set-mss 1400

UDP server:

ipyrf udp server 0.0.0.0 --port 12345

UDP client (with bandwidth cap and optional payload size):

ipyrf udp client 127.0.0.1 --port 12345 --bandwidth 50M --time 5
ipyrf udp client 127.0.0.1 --port 12345 --bandwidth 50M --time 5 -l 1200

Interactive mode

You can run clients in an interactive mode that lets you adjust the pacing live using your keyboard. Use --interactive and optionally --interval (seconds between stats updates). When interactive is enabled, the same client logic is used underneath with a dynamic pacing controller.

Controls shown in the terminal:

• ←: -1 Mbps

• →: +1 Mbps

• ↓: -10%

• ↑: +10%

• 0: reset to initial bandwidth (or unlimited for TCP if none was provided)

• u: unlimited (disable pacing)

• q: quit

Examples:

# TCP interactive (unlimited unless you pass --bandwidth)
ipyrf tcp client 127.0.0.1 --port 5201 --interactive

# TCP interactive with initial pacing and custom interval
ipyrf tcp client 127.0.0.1 --port 5201 --bandwidth 200M --set-mss 1400 --interactive --interval 0.5

# UDP interactive (requires initial --bandwidth)
ipyrf udp client 127.0.0.1 --port 5201 --bandwidth 50M -l 1200 --interactive

CLI overview

Top-level structure:

ipyrf [tcp|udp] [server|client] [OPTIONS]

Common options (both protocols, both roles):

• --port: Port (default 5201)

• --logfile: Redirect output to a file

• --json_log: Emit logs in JSON (newline-delimited)

TCP-specific options:

• tcp server ADDRESS: Start a TCP server on ADDRESS

• tcp client ADDRESS: Start a TCP client to connect to ADDRESS

• --congestion-control: Select Linux TCP CC algorithm if available

• --time: Test duration (seconds), default 10

• --bandwidth: Target rate (e.g., 50M); used for pacing, optional

• --set-mss: Set approximate MSS via TCP_MAXSEG

• --interactive: Enable interactive pacing controls

• --interval: Stats interval in seconds for interactive mode (default 1.0)

UDP-specific options:

• udp server ADDRESS: Start a UDP server on ADDRESS

• udp client ADDRESS: Start a UDP client to ADDRESS

• --time: Test duration (seconds), default 10

• --bandwidth: Target rate (required for UDP client; e.g., 50M)

• -l/--length: UDP payload length (default 1200)

• --interactive: Enable interactive pacing controls

• --interval: Stats interval in seconds for interactive mode (default 1.0)

JSON logging

Add --json_log to switch all output to newline-delimited JSON objects. This is useful for machine parsing or dashboards. Example:

ipyrf tcp client 127.0.0.1 --time 5 --json_log | jq

Notes

• Output is JSON (newline-delimited for update events) when --json_log is given; otherwise, a human-readable summary is printed.

• UDP mode sends a FIN marker at the end and the server exits after FIN (or inactivity timeout).

• On Linux, congestion control selection is exposed if /proc entries are available.

License

MIT. See LICENSE.