btest-rs/docs/user-guide.md

btest-rs User Guide

Quick Start

# Server mode (MikroTik connects to you)
btest -s

# Client mode (you connect to MikroTik)
btest -c 192.168.88.1 -r

Server Mode

Run btest-rs as a server and let MikroTik devices connect for bandwidth testing.

Basic Server

btest -s

Listens on TCP port 2000 (default). Any MikroTik device can connect without authentication.

Server with Authentication

btest -s -a admin -p mysecretpassword

MikroTik devices must provide matching credentials. Uses MD5 challenge-response authentication.

Custom Port

btest -s -P 3000

Verbose/Debug Output

btest -s -v      # Show connection info and debug messages
btest -s -vv     # Show hex dumps of status exchange (for debugging)

MikroTik Configuration (connecting to our server)

Important: Always set Connection Count to 1. Multi-connection mode is not supported and will cause severely degraded speeds.

On the MikroTik device (WinBox or CLI):

# CLI — always include connection-count=1
/tool/bandwidth-test address=<server-ip> direction=both protocol=udp user=admin password=mysecretpassword connection-count=1

Or via WinBox: Tools → Bandwidth Test, enter server address, credentials, set Connection Count to 1, and click Start.

Client Mode

Connect to a MikroTik device's built-in bandwidth test server.

Prerequisites

Enable btest server on MikroTik:

/tool/bandwidth-server set enabled=yes

Note: If the MikroTik uses RouterOS >= 6.43 with authentication enabled, you'll need to either disable auth or use credentials. EC-SRP5 auth is not yet supported; MD5 auth works on older RouterOS versions.

Download Test (receive)

btest -c 192.168.88.1 -r

Measures download speed from MikroTik to your machine.

Upload Test (transmit)

btest -c 192.168.88.1 -t

Measures upload speed from your machine to MikroTik.

Bidirectional Test

btest -c 192.168.88.1 -t -r

Tests both directions simultaneously.

UDP Mode

btest -c 192.168.88.1 -r -u          # UDP download
btest -c 192.168.88.1 -t -u          # UDP upload
btest -c 192.168.88.1 -t -r -u       # UDP bidirectional

Bandwidth Limiting

btest -c 192.168.88.1 -r -b 100M     # Limit to 100 Mbps
btest -c 192.168.88.1 -t -b 1G       # Limit to 1 Gbps
btest -c 192.168.88.1 -r -b 500K     # Limit to 500 Kbps

NAT Traversal

If you're behind NAT and need to receive UDP data:

btest -c 192.168.88.1 -r -u -n

The -n flag sends a probe packet to open the NAT firewall hole.

With Authentication

btest -c 192.168.88.1 -r -a admin -p password

Reading the Output

[   1]  TX  264.50 Mbps (33062912 bytes)
[   2]  TX  263.98 Mbps (32997376 bytes)
[   2]  RX  263.98 Mbps (32997012 bytes)
[   3]  RX  430.51 Mbps (53813376 bytes)  lost: 5

Field	Meaning
[ N]	Interval number (1 per second)
TX	Data we sent (upload)
RX	Data we received (download)
Mbps	Megabits per second
bytes	Raw bytes transferred in this interval
lost: N	UDP packets lost (UDP mode only)

CLI Reference

btest-rs — MikroTik Bandwidth Test server & client in Rust

Usage: btest [OPTIONS]

Options:
  -s, --server              Run in server mode
  -c, --client <HOST>       Run in client mode, connect to HOST
  -t, --transmit            Client: upload test
  -r, --receive             Client: download test
  -u, --udp                 Use UDP instead of TCP
  -b, --bandwidth <BW>      Bandwidth limit (e.g., 100M, 1G, 500K)
  -P, --port <PORT>         Port number [default: 2000]
  -a, --authuser <USER>     Authentication username
  -p, --authpass <PASS>     Authentication password
  -n, --nat                 NAT traversal mode
  -v, --verbose             Increase log verbosity (-v, -vv)
  -h, --help                Show help
  -V, --version             Show version

Tips

• Connection Count MUST be 1 when MikroTik connects to your server. Multi-connection mode is not supported and will cause speeds to drop to near zero. Single-connection performance is excellent (1+ Gbps).
• TCP mode generally gives more stable results than UDP due to TCP flow control.
• UDP mode is better for measuring raw link capacity without TCP overhead.
• First interval may show higher or lower numbers as the connection stabilizes. Look at intervals 3+ for steady-state throughput.
• WiFi testing: bidirectional tests on WiFi will show lower per-direction speeds because WiFi is half-duplex at the MAC layer.

Troubleshooting

Problem	Solution
EC-SRP5 authentication not supported	Disable auth on MikroTik btest server, or use older RouterOS
Connection refused	Check port 2000 is open, firewall allows it
Server shows 0 RX	Check MikroTik is actually sending (direction setting)
Speed drops over time (server mode)	Set Connection Count to 1 on MikroTik. Multi-connection is not supported
Very low speed with multiple connections	Multi-connection mode is broken — set Connection Count to 1
UDP lost packets high	Network congestion or MTU issues, try reducing bandwidth with -b