定义最大数据包大小（以字节为单位，包括有效负载和所有标头）。数据包内可包含多条消息。默认值 = 1500。
Note that this default value is suitable for local testing only. Usually you should change this value; a recommended setting for PC or mobile is 1470. For games consoles this value should probably be less than ~1100. Wrong size definition can cause packet dropping.
using UnityEngine;
using UnityEngine.Networking;
public class ExampleScript : NetworkBehaviour
{
void Start()
{
ConnectionConfig myConfig = new ConnectionConfig();
myConfig.AddChannel(QosType.Unreliable);
myConfig.AddChannel(QosType.UnreliableFragmented);
myConfig.PacketSize = 1440;
}
}