About WAN bonding servers

A WAN bonding server is the endpoint system that manages and reassembles data traffic from multiple WAN connections that have been combined (or bonded) by a WAN bonding client, such as a Digi router. It acts as the central aggregation point for all bonded tunnels, maintaining session integrity, balancing traffic, and ensuring packets from different WAN links are combined back into a single, reliable data stream.

A WAN bonding server is what makes WAN bonding work. It’s the remote partner to your Digi device — receiving traffic from multiple WAN interfaces, rebuilding it in order, and forwarding it to its final destination (like the internet or a private network).

Without this server, bonded data streams would have nowhere to terminate or synchronize, and the bonding process couldn’t function.

The WAN bonding server:

  • Receives encrypted tunnels from multiple WAN interfaces on the bonding client (e.g., Cellular + Ethernet + Wi-Fi WAN).

  • Combines data packets from each interface into a single coherent stream.

  • Monitors performance metrics (latency, jitter, loss) for each path.

  • Balances traffic across WAN links based on bonding mode (speed, latency, or reliability optimized).

  • Reassembles packets in order, compensating for delay and loss differences between links.

  • Sends the unified traffic stream to its intended destination — typically through a single public IP.

Digi router (bonding client)

  • Splits outgoing packets across multiple WAN links (Ethernet, Cellular, etc.)

  • Encrypts and sends packets to the WAN Bonding Server

WAN bonding server

  • Receives packets from all links

  • Reorders and reconstructs the complete data stream

  • Delivers it to the destination (internet or LAN host)

A WAN bonding server is a customer-deployed server (on-premises or in the cloud) that you manage yourself or hire someone else to do it for you. See WAN bonding server options for more information.

  • Used for private networks or custom routing control

  • Requires a WAN Bonding License Key to activate and authorize bonding functionality

Function

Purpose
Session management Maintains secure tunnels with each bonding client.
Traffic reassembly Combines packets from multiple WAN interfaces into a single flow.
Link monitoring Tracks bandwidth, latency, and packet loss per interface.
Load balancing Dynamically allocates packets to the best-performing links.
Error correction Compensates for loss or delay using redundancy and retransmission.
Encryption Secures bonded traffic between client and server.

Statistics reporting

Sends bonding performance metrics back to Digi Remote Manager.

Without the WAN bonding server:

  • Each WAN link would operate independently, without a central point to synchronize and combine data.

  • The router couldn’t maintain session continuity if one link fails.

  • Performance and reliability improvements of bonding would not be possible.

The server ensures that your multiple WAN connections behave as one logical, intelligent, resilient connection.