Limits and Performance Characteristics

Configurable Limits

Parameter	Config Key	Default	Description
Max Hops	routing.max_hops	16	Maximum hops for route advertisements
Route TTL	routing.route_ttl	5m	Route expiration time
Advertise Interval	routing.advertise_interval	2m	Route advertisement frequency
Node Info Interval	routing.node_info_interval	2m	Node info frequency
Stream Open Timeout	limits.stream_open_timeout	30s	Stream open round-trip time
Buffer Size	limits.buffer_size	256 KB	Per-stream buffer at each hop
Max Streams/Peer	limits.max_streams_per_peer	1000	Concurrent streams per peer
Max Total Streams	limits.max_streams_total	10000	Total concurrent streams
Max Pending Opens	limits.max_pending_opens	100	Pending stream opens
Idle Threshold	connections.idle_threshold	5m	Keepalive interval
Connection Timeout	connections.timeout	90s	Keepalive timeout

Protocol Constants (Non-configurable)

Constant	Value	Description
Max Frame Payload	16 KB	Maximum payload per frame
Max Frame Size	16398 bytes	Payload + 14-byte header
Header Size	14 bytes	Frame header size
Protocol Version	0x01	Current wire protocol version
Control Stream ID	0	Reserved for control channel

Proxy Chain Practical Limits

Important: max_hops only limits route advertisement propagation, NOT stream path length. Stream paths are limited by the 30-second open timeout.

Use Case	Recommended Max Hops	Limiting Factor
Interactive SSH	8-12 hops	Latency (5-50ms per hop)
Video Streaming	6-10 hops	Buffering (256KB × hops)
Bulk Transfer	12-16 hops	Throughput (16KB chunks)
High-latency WAN	4-6 hops	30s stream open timeout

Per-hop overhead:

• Latency: +1-5ms (LAN), +50-200ms (WAN)
• Memory: +256KB buffer per active stream
• CPU: Frame decode/encode at each relay

Topology Support

The flood-based routing supports arbitrary mesh topologies:

• Linear chains: A → B → C → D
• Tree structures: A → B → C and A → B → D
• Full mesh: Any agent to any agent
• Redundant paths: Multiple paths (lowest metric wins)

Loop prevention via SeenBy lists in route advertisements.

Prometheus Metrics

All metrics prefixed with muti_metroo_.

Connection Metrics

• peers_connected (gauge): Connected peers
• peers_total (counter): Total peer connections
• peer_connections_total (counter): By transport/direction
• peer_disconnects_total (counter): By reason

Stream Metrics

• streams_active (gauge): Active streams
• streams_opened_total (counter): Total streams opened
• streams_closed_total (counter): Total streams closed
• stream_open_latency_seconds (histogram): Open latency
• stream_errors_total (counter): By error type

Data Transfer Metrics

• bytes_sent_total (counter): By type
• bytes_received_total (counter): By type
• frames_sent_total (counter): By frame type
• frames_received_total (counter): By frame type

Routing Metrics

• routes_total (gauge): Routes in table
• route_advertises_total (counter): Advertisements processed
• route_withdrawals_total (counter): Withdrawals processed
• route_flood_latency_seconds (histogram): Flood latency

SOCKS5 Metrics

• socks5_connections_active (gauge): Active connections
• socks5_connections_total (counter): Total connections
• socks5_auth_failures_total (counter): Auth failures
• socks5_connect_latency_seconds (histogram): Connect latency

Exit Handler Metrics

• exit_connections_active (gauge): Active exit connections
• exit_connections_total (counter): Total exit connections
• exit_dns_queries_total (counter): DNS queries
• exit_dns_latency_seconds (histogram): DNS latency
• exit_errors_total (counter): By error type

Protocol Metrics

• handshake_latency_seconds (histogram): Handshake time
• handshake_errors_total (counter): By error type
• keepalives_sent_total (counter): Keepalives sent
• keepalives_received_total (counter): Keepalives received
• keepalive_rtt_seconds (histogram): Round-trip time

RPC Metrics

• rpc_calls_total (counter): By result and command
• rpc_call_duration_seconds (histogram): By command
• rpc_bytes_received_total (counter): Request bytes
• rpc_bytes_sent_total (counter): Response bytes