This article explains how Ditto manages redundant Bluetooth Low Energy (LE) connections within the mesh network by default, the tradeoffs with mesh size in mind, and how to deviate from this default behavior so you can ensure continuous sync uptime in your mesh:

By default, if a peer is already connected through a transport other than Bluetooth LE, such as LAN, Apple Wireless Direct Link (AWDL), and so on, Ditto avoids these redundant connections to ensure optimal sync performance in the mesh.

Maintaining redundant Bluetooth LE connections can impact sync performance, especially in larger meshes with approximately 65 to 100 devices or more, where increased network overhead may cause a slowdown in the data replication process.

However, in some use cases, such as the point-of-sale (PoS) system, where continuous operation is mission-critical, the benefits of having fallback connections outweigh this loss in sync performance.

For example, in a PoS system, maintaining redundant connections may be preferred since any delay in establishing a mesh connection if Wi-Fi becomes unavailable negatively affects business operations.

To change the default behavior and enable redundant connections, set the system parameter mesh_chooser_avoid_redundant_bluetooth to false: