ConnectionConfig.OverflowDropThreshold

Description

Defines the percentage (from 0 to 100) of packets that need to be dropped due to lack of space in internal buffers before the SendUpdate timeout is automatically increased (and send rate is automatically decreased). Default value = 5.

To avoid receiver overflow, Unity Multiplayer supports flow control. Each ping packet sent between connected peers contains two values:
(1) Packets lost due to network conditions.
(2) Packets lost because the receiver does not have free space in its incoming buffers.
Like NetworkDropThreshold, both values are reported in percent. Use NetworkDropThreshold and OverflowDropThreshold to set thresholds for these values. If a value reported in the ping packet exceeds the corresponding threshold, Unity Multiplayer increases the sending timeout for packets up to a maximum value of DisconnectTimeout.

Note: wireless networks usually exhibit 5% or greater packet loss. For wireless networks it is advisable to use a NetworkDropThreshold of 40-50%.

using UnityEngine;
using UnityEngine.Networking;

public class ExampleScript : NetworkBehaviour
{
    void Start()
    {
        ConnectionConfig myConfig = new ConnectionConfig();
        myConfig.AddChannel(QosType.Unreliable);
        myConfig.AddChannel(QosType.UnreliableFragmented);
        myConfig.NetworkDropThreshold = 50;         //50%
        myConfig.OverflowDropThreshold = 10;         //10%
    }
}