Why MeshCore Scales Better Than Flooding

Understanding the difference between MeshCore's flood-first, direct-route-after routing and Meshtastic's flood routing explains why the two protocols behave differently in large networks.

Flood Routing (Meshtastic)

• In a managed flood, each relay rebroadcasts each new message once — duplicates are suppressed (a node will not re-send a message it has already seen), and non-relay roles do not rebroadcast at all.
• Air time consumed grows with every additional relay node.
• Channel utilization increases as the network grows - more nodes means more congestion.
• Works well in small networks; degrades in large or dense deployments.

Flood-First, Direct-Route-After Routing (MeshCore)

• The first message to a destination is flooded (and the path is learned as a byproduct); subsequent unicast messages follow the learned path, so only nodes on that path retransmit them.
• Air time per unicast message is bounded once a path is known.
• For stable links carrying repeat unicast traffic, established paths reduce retransmissions over time. Under mobility or link churn, paths break and the sender re-floods to re-learn them, which can increase traffic — the quieting effect is not guaranteed.
• Targeted unicast forwarding avoids the per-message flooding cost, but advertisements and group/broadcast traffic still flood and grow with network size. Real-world scaling depends heavily on topology stability and broadcast volume; no specific large-network guarantee is implied.

Side-by-Side Comparison

Practical Implications

• Power consumption - Infrastructure repeaters on MeshCore consume less power per forwarded unicast message at scale because they are silent when not on an active path.
• Frequency reuse - Less channel congestion from repeat unicast traffic means the same frequency can support more simultaneous conversations.
• Latency - Once a path is established, latency is lower than re-flooding each message, but it still varies with channel congestion, half-duplex contention, duty-cycle limits, and hop count, and resets to a full re-discovery delay whenever a path breaks. Do not assume consistent or bounded latency.
• Dense deployments - In city-wide or event-scale deployments, MeshCore's targeted forwarding reduces the broadcast-storm pressure that can make large Meshtastic networks unreliable, though group/broadcast traffic still floods.