Reimplement pinging via the orders channel.

OpenRA.Game/Network/Order.cs

@@ -199,7 +199,12 @@ namespace OpenRA
 		{
 			return new Order("HandshakeResponse", null, false) { IsImmediate = true, TargetString = text };
 		}
-		
+
+		public static Order Pong(string pingTime)
+		{
+			return new Order("Pong", null, false) { IsImmediate = true, TargetString = pingTime };
+		}
+
 		public static Order PauseGame(bool paused)
 		{
 			return new Order("PauseGame", null, false) { TargetString = paused ? "Pause" : "UnPause" };

OpenRA.Game/Network/Session.cs

@@ -62,6 +62,8 @@ namespace OpenRA.Network
 			public bool IsReady { get { return State == ClientState.Ready; } }
 			public bool IsObserver { get { return Slot == null; } }
 			public int Ping = -1;
+			public int PingJitter = -1;
+			public int[] PingHistory = {};
 		}
 
 		public class Slot

OpenRA.Game/Network/UnitOrders.cs

@@ -190,6 +190,11 @@ namespace OpenRA.Network
 							Game.Debug("{0} has reciprocated",targetPlayer.PlayerName);
 						}
 
+						break;
+					}
+				case "Ping":
+					{
+						orderManager.IssueOrder(Order.Pong(order.TargetString));
 						break;
 					}
 				default: