Protocol Overview
Muti Metroo uses a binary frame-based protocol for all peer communication.
Protocol Version
Current version: 0x01
Frame Structure
Every frame has a 14-byte header followed by variable-length payload:
| Offset | Size | Field | Description |
|---|---|---|---|
| 0 | 1 byte | Type | Frame type identifier |
| 1 | 1 byte | Flags | Frame flags (e.g., FIN_WRITE, FIN_READ) |
| 2-5 | 4 bytes | Length | Payload length (big-endian) |
| 6-13 | 8 bytes | StreamID | Stream identifier (big-endian) |
| 14+ | variable | Payload | Frame payload (0-16384 bytes) |
Frame Types
See Frame Types for complete list.
Constants
| Constant | Value | Description |
|---|---|---|
| Protocol Version | 0x01 | Current protocol version |
| Max Frame Payload | 16 KB | Maximum payload size |
| Header Size | 14 bytes | Fixed header size |
| Control Stream ID | 0 | Reserved for control channel |
Stream ID Allocation
- Connection initiator (dialer): ODD IDs (1, 3, 5, ...)
- Connection acceptor (listener): EVEN IDs (2, 4, 6, ...)
- StreamID 0: Reserved for control messages
Connection Lifecycle
- Handshake: PEER_HELLO / PEER_HELLO_ACK exchange
- Operation: Stream and control frames
- Keepalive: KEEPALIVE / KEEPALIVE_ACK when idle
- Disconnect: Connection close or timeout
Timeouts
| Operation | Timeout |
|---|---|
| Handshake | 10s |
| Stream open | 30s |
| Keepalive interval | 5m |
| Keepalive timeout | 90s |
| Idle stream | 5m |
See Limits for complete limits reference.