Why MeshCore Scales Better Than Flooding

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

Flood Routing (Meshtastic)

• EveryIn a managed flood, each relay rebroadcasts each new message once — duplicates are suppressed (a node retransmitswill everynot re-send a message it receives.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.

Path-DiscoveryFlood-First, Direct-Route-After Routing (MeshCore)

• OnlyThe 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 the establishedthat path retransmit unicast messages.them.
• Air time per unicast message is bounded once a path is known.
• TheFor morestable twolinks nodescarrying communicate,repeat theunicast fewertraffic, established paths reduce retransmissions are needed - the network gets quieter 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.
• ScalesTargeted tounicast largeforwarding networksavoids withoutthe proportionalper-message growthflooding incost, radiobut traffic.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

Attribute	MeshCore (path-discovery)flood-first, direct-route-after)	Meshtastic (flooding)
First message to unknown node	Floods (once)	Floods (always)
Subsequent messages to known node	Path-only retransmissions	Floods (always)
Congestion as network grows	LowLower -for reducesrepeat withunicast; usegroup/broadcast still floods	High - grows with nodes
Average power per message at scale	Lower	Higher
Group / broadcast messages	Flood	Flood
Route failure recovery	Re-floodsOn afterrepeated 3ACK retriesfailure the path is reset to flood, and the next message re-discovers a route (the exact retry count is firmware/config dependent). Each recovery incurs a full flood, briefly increasing channel load.	N/A - always floods

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.
• Predictable latencyLatency - Once a path is established, message delivery latency is consistent;lower than re-flooding each message, but it doesstill 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 dependassume onconsistent howor manybounded nodes happen to be awake.latency.
• Dense deployments - In city-wide or event-scale deployments, MeshCore's approachtargeted avoidsforwarding reduces the broadcast broadcast-storm problempressure that can make large Meshtastic networks unreliable.unreliable, though group/broadcast traffic still floods.