When tcp_conn_count > 0, the auth OK response includes a session
token in bytes 1-2: [01, HI, LO, 00] instead of [01, 00, 00, 00].
MikroTik checks these bytes to determine multi-connection support.
Primary connection: full handshake, receives session token
Secondary connections: auth with same token, join the session
Server waits up to 10s for all connections to join before starting.
This fixes MikroTik showing "test unsupported" for TCP multi-conn.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Full reimplementation of the MikroTik Bandwidth Test protocol:
- Server mode: accepts connections from MikroTik devices on port 2000
- Client mode: connects to MikroTik btest servers
- TCP and UDP protocols with bidirectional support
- MD5 challenge-response authentication
- Dynamic speed adjustment (1.5x algorithm)
- Status exchange matching original C pselect() behavior
- Docker support with multi-stage build
Tested against MikroTik RouterOS achieving:
- 1.05 Gbps server RX (single connection)
- 530 Mbps client TCP download
- 840 Mbps client TCP upload
- 433 Mbps client UDP download
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
