Link Simulator

Rust tool for simulating an arbitrary connection between two network endpoints.

Features:

Any number of simultaneous connections with individual configurations
Configurable delay per link
Data mutation based on a fixed bit error rate to simulate space RF links
Rate control (excess incoming bytes are dropped)
Efficiency through zero-copy forwarding of all data packets
Network configuration via config files
Extensive network performance insight:
- Received bytes & packets
- Dropped bytes & packets
- Forwarded bytes & packets
- Actual bandwidth
- Internal buffer occupancy
- Mutated bits (flips)
Optional Grafana integration for monitoring

Build Instructions

Install Rust on your system, then simply execute

cargo build --release

in the project's root folder to build the executable and the test programs.

Usage

Run the executable link_simulator (found in /target/release) with a routes configuration file according to the following syntax:

link_simulator [options] <file>

options:
    -i              Print link info on startup
    -s              Print link statistics to stdout
					(only works on terminals with 60+ chars per line)
					(does not work on Windows)
    -gLINK_NAME     Send link statistics to Grafana for specified link
                    (repeat this option if needed)
    -G              Send statistics of all links to Grafana
    -p              Discard packet if bit is flipped

<file> must have the following format:
    link_name address_in address_out bit_error_rate delay_ms max_bandwidth
    ...
    ...
(lines starting with '#' are ignored)
line format:
    link_name:          String (without spaces)
    address_{in/out}:   IPv4:Port
    bit_error_rate:     float (0.0 ... 1.0(
    delay_ms:           integer [ms]
    max_bandwidth:      float [bps]
example:
    Test_route localhost:2000 localhost:2001 1e-5 2000 1000000

an example routes configuration file (routes.config) is provided in the project directory.

Grafana Integration

First, set up InfluxDB and Grafana

Influx DB must listen for input at UDP 127.0.0.1:8100
Grafana must be connected to Influx DB and the provided config file must be loaded (/grafana/link_simulator.json)

Testing locally

Terminal window #1:

./target/release/link_test_receiver

Terminal window #2:

./target/release/link_simulator -i routes.config

Terminal window #3:

./target/release/link_test_sender 800

The sender (#3) will continuously send packets over the Test_route link at a rate of 800kbps. The link should indicate the reception and forwarding of packets, a rate and applied bitflips (#2). The receiver (#1) should also indicate received data 2 seconds after starting the sender (configured delay in routes.config).

Test success criteria

Terminate (Ctrl+C) the sender (#3), wait at least 2s (or other configured delay), then terminate the receiver (#1).