diff --git a/mixnet/node.py b/mixnet/node.py
index 054b85ba..defd5b36 100644
--- a/mixnet/node.py
+++ b/mixnet/node.py
@@ -27,8 +27,10 @@
 # 32-byte that represents an IP address and a port of a mix node.
 NodeAddress: TypeAlias = bytes
 
-InboundSocket: TypeAlias = "queue.Queue[SphinxPacket]"
-OutboundSocket: TypeAlias = "queue.Queue[Tuple[NodeAddress, SphinxPacket | Payload]]"
+PacketQueue: TypeAlias = "queue.Queue[Tuple[NodeAddress, SphinxPacket]]"
+PacketPayloadQueue: TypeAlias = (
+    "queue.Queue[Tuple[NodeAddress, SphinxPacket | Payload]]"
+)
 
 
 @dataclass
@@ -49,8 +51,8 @@ def sphinx_node(self) -> Node:
     def start(
         self,
         delay_rate_per_min: int,
-        inbound_socket: InboundSocket,
-        outbound_socket: OutboundSocket,
+        inbound_socket: PacketQueue,
+        outbound_socket: PacketPayloadQueue,
     ) -> MixNodeRunner:
         thread = MixNodeRunner(
             self.encryption_private_key,
@@ -74,8 +76,8 @@ def __init__(
         self,
         encryption_private_key: X25519PrivateKey,
         delay_rate_per_min: int,  # Poisson rate parameter: mu
-        inbound_socket: InboundSocket,
-        outbound_socket: OutboundSocket,
+        inbound_socket: PacketQueue,
+        outbound_socket: PacketPayloadQueue,
     ):
         super().__init__()
         self.encryption_private_key = encryption_private_key
@@ -89,7 +91,7 @@ def run(self) -> None:
         # In the real implementation, consider implementing this in asynchronous if possible,
         # to approximate a M/M/inf queue
         while True:
-            packet = self.inbound_socket.get()
+            _, packet = self.inbound_socket.get()
             thread = MixNodePacketProcessor(
                 packet,
                 self.encryption_private_key,
@@ -124,7 +126,7 @@ def __init__(
         packet: SphinxPacket,
         encryption_private_key: X25519PrivateKey,
         delay_rate_per_min: int,  # Poisson rate parameter: mu
-        outbound_socket: OutboundSocket,
+        outbound_socket: PacketPayloadQueue,
         num_processing: AtomicInt,
     ):
         super().__init__()
diff --git a/mixnet/test_node.py b/mixnet/test_node.py
index 6cebb4da..8783e9d7 100644
--- a/mixnet/test_node.py
+++ b/mixnet/test_node.py
@@ -12,7 +12,7 @@
 
 from mixnet.bls import generate_bls
 from mixnet.mixnet import Mixnet, MixnetTopology
-from mixnet.node import InboundSocket, MixNode, OutboundSocket
+from mixnet.node import MixNode, NodeAddress, PacketPayloadQueue, PacketQueue
 from mixnet.packet import PacketBuilder
 from mixnet.poisson import poisson_interval_sec, poisson_mean_interval_sec
 from mixnet.utils import random_bytes
@@ -29,8 +29,8 @@ def test_mixnode_runner_emission_rate(self):
         the rate of outputs should be `lambda`.
         """
         mixnet, topology = self.init()
-        inbound_socket: InboundSocket = queue.Queue()
-        outbound_socket: OutboundSocket = queue.Queue()
+        inbound_socket: PacketQueue = queue.Queue()
+        outbound_socket: PacketPayloadQueue = queue.Queue()
 
         packet, route = PacketBuilder.real(b"msg", mixnet, topology).next()
 
@@ -43,7 +43,13 @@ def test_mixnode_runner_emission_rate(self):
         emission_rate_per_min = 120  # lambda (= 2msg/sec)
         sender = threading.Thread(
             target=self.send_packets,
-            args=(inbound_socket, packet, packet_count, emission_rate_per_min),
+            args=(
+                inbound_socket,
+                packet,
+                route[0].addr,
+                packet_count,
+                emission_rate_per_min,
+            ),
         )
         sender.daemon = True
         sender.start()
@@ -82,14 +88,15 @@ def test_mixnode_runner_emission_rate(self):
 
     @staticmethod
     def send_packets(
-        inbound_socket: InboundSocket,
+        inbound_socket: PacketQueue,
         packet: SphinxPacket,
+        node_addr: NodeAddress,
         cnt: int,
         rate_per_min: int,
     ):
         for _ in range(cnt):
             time.sleep(poisson_interval_sec(rate_per_min))
-            inbound_socket.put(packet)
+            inbound_socket.put((node_addr, packet))
 
     @staticmethod
     def init() -> Tuple[Mixnet, MixnetTopology]: