diff --git a/ClientTester/EchoClientTester/DummyService/DummyClients.cs b/ClientTester/EchoClientTester/DummyService/DummyClients.cs
index 0944d41..1a4adeb 100644
--- a/ClientTester/EchoClientTester/DummyService/DummyClients.cs
+++ b/ClientTester/EchoClientTester/DummyService/DummyClients.cs
@@ -91,8 +91,6 @@ public class DummyClients
             packetHeader.BodyLength = 4 + sizeof(long);
             writer.Put(clientId);
             peer.Send(writer, DeliveryMethod.ReliableOrdered);
-
-            // 초기화
         };
 
         listener.NetworkReceiveEvent += (peer, reader, channel, deliveryMethod) =>
@@ -176,27 +174,23 @@ public class DummyClients
         int seq = seqNumber++;
         pendingPings[seq] = Stopwatch.GetTimestamp();
 
-        // 응답 없는 오래된 ping 정리 (패킷 유실 시 메모리 누수 방지)
-        if (pendingPings.Count > MAX_PENDING_PINGS)
+        TransformPlayerPacket transformPlayerPacket = new TransformPlayerPacket
         {
-            int cutoff = seq - MAX_PENDING_PINGS;
-            foreach (int key in pendingPings.Keys)
+            PlayerId = (int)clientId,
+            RotY = rotY,
+            Position = new Packet.Vector3
             {
-                if (key < cutoff)
-                {
-                    pendingPings.TryRemove(key, out _);
-                }
+                X = position.X,
+                Y = 0, // 높이는 버린다.
+                Z = position.Z
             }
-        }
+        };
 
-        PacketHeader packetHeader = new PacketHeader();
-        packetHeader.Code = 0;
-        packetHeader.BodyLength = (ushort)$"Echo seq:{seq}".Length;
-        writer.Put((short)packetHeader.Code);
-        writer.Put((short)packetHeader.BodyLength);
-        writer.Put($"Echo seq:{seq}");
-        // 순서보장 안함 HOL Blocking 제거
-        peer.Send(writer, DeliveryMethod.ReliableUnordered);
+        // Protobuf 직렬화 + 헤더 조립
+        byte[] data = PacketSerializer.Serialize((ushort)PacketCode.TRANSFORM_PLAYER, transformPlayerPacket);
+        writer.Put(data);
+        // 이동은 손실 감수함
+        peer.Send(writer, DeliveryMethod.Unreliable);
         SentCount++;
         writer.Reset();
     }