diff --git a/libp2p/network/swarm.py b/libp2p/network/swarm.py
index badd16c8..e4d71a6d 100644
--- a/libp2p/network/swarm.py
+++ b/libp2p/network/swarm.py
@@ -177,8 +177,8 @@ class Swarm(INetwork):
                 Call listener listen with the multiaddr
                 Map multiaddr to listener
         """
-        for multiaddr in multiaddrs:
-            if str(multiaddr) in self.listeners:
+        for maddr in multiaddrs:
+            if str(maddr) in self.listeners:
                 return True
 
             async def conn_handler(
@@ -187,8 +187,8 @@ class Swarm(INetwork):
                 # Upgrade reader/write to a net_stream and pass \
                 # to appropriate stream handler (using multiaddr)
                 raw_conn = RawConnection(
-                    multiaddr.value_for_protocol("ip4"),
-                    multiaddr.value_for_protocol("tcp"),
+                    maddr.value_for_protocol("ip4"),
+                    maddr.value_for_protocol("tcp"),
                     reader,
                     writer,
                     False,
@@ -215,19 +215,19 @@ class Swarm(INetwork):
             try:
                 # Success
                 listener = self.transport.create_listener(conn_handler)
-                self.listeners[str(multiaddr)] = listener
-                await listener.listen(multiaddr)
+                self.listeners[str(maddr)] = listener
+                await listener.listen(maddr)
 
                 # Call notifiers since event occurred
                 for notifee in self.notifees:
-                    await notifee.listen(self, multiaddr)
+                    await notifee.listen(self, maddr)
 
                 return True
             except IOError:
                 # Failed. Continue looping.
-                print("Failed to connect to: " + str(multiaddr))
+                print("Failed to connect to: " + str(maddr))
 
-        # No multiaddr succeeded
+        # No maddr succeeded
         return False
 
     def notify(self, notifee: INotifee) -> bool:
diff --git a/libp2p/protocol_muxer/multiselect.py b/libp2p/protocol_muxer/multiselect.py
index c854415f..8ce66d93 100644
--- a/libp2p/protocol_muxer/multiselect.py
+++ b/libp2p/protocol_muxer/multiselect.py
@@ -79,7 +79,9 @@ class Multiselect(IMultiselectMuxer):
 
         # Confirm that the protocols are the same
         if not validate_handshake(handshake_contents):
-            raise MultiselectError("multiselect protocol ID mismatch")
+            raise MultiselectError(
+                f"multiselect protocol ID mismatch: handshake_contents={handshake_contents}"
+            )
 
         # Handshake succeeded if this point is reached
 
diff --git a/libp2p/security/insecure/transport.py b/libp2p/security/insecure/transport.py
index 5f00fc10..7f26820e 100644
--- a/libp2p/security/insecure/transport.py
+++ b/libp2p/security/insecure/transport.py
@@ -5,7 +5,7 @@ from libp2p.security.base_session import BaseSession
 from libp2p.security.base_transport import BaseSecureTransport
 from libp2p.security.secure_conn_interface import ISecureConn
 from libp2p.typing import TProtocol
-from libp2p.utils import encode_varint_prefixed, read_varint_prefixed_bytes
+from libp2p.utils import encode_fixedint_prefixed, read_fixedint_prefixed
 
 from .exceptions import UpgradeFailure
 from .pb import plaintext_pb2
@@ -20,12 +20,15 @@ class InsecureSession(BaseSession):
     # FIXME: Update the read/write to `BaseSession`
     async def run_handshake(self):
         msg = make_exchange_message(self.local_private_key.get_public_key())
-        self.writer.write(encode_varint_prefixed(msg.SerializeToString()))
+        msg_bytes = msg.SerializeToString()
+        encoded_msg_bytes = encode_fixedint_prefixed(msg_bytes)
+        self.writer.write(encoded_msg_bytes)
         await self.writer.drain()
 
-        msg_bytes_other_side = await read_varint_prefixed_bytes(self.reader)
+        msg_bytes_other_side = await read_fixedint_prefixed(self.reader)
         msg_other_side = plaintext_pb2.Exchange()
         msg_other_side.ParseFromString(msg_bytes_other_side)
+
         # TODO: Verify public key with peer id
         # TODO: Store public key
         self.remote_peer_id = ID(msg_other_side.id)
diff --git a/libp2p/utils.py b/libp2p/utils.py
index cb7c4850..5fbc8ac5 100644
--- a/libp2p/utils.py
+++ b/libp2p/utils.py
@@ -4,7 +4,7 @@ from typing import Tuple
 
 from libp2p.typing import StreamReader
 
-TIMEOUT = 1
+TIMEOUT = 10
 
 
 def encode_uvarint(number: int) -> bytes:
@@ -64,7 +64,8 @@ async def read_varint_prefixed_bytes(
     return await reader.read(len_msg)
 
 
-# Delimited read/write
+# Delimited read/write, used by multistream-select.
+# Reference: https://github.com/gogo/protobuf/blob/07eab6a8298cf32fac45cceaac59424f98421bbc/io/varint.go#L109-L126  # noqa: E501
 
 
 def encode_delim(msg_str: str) -> bytes:
@@ -75,3 +76,20 @@ def encode_delim(msg_str: str) -> bytes:
 async def read_delim(reader: StreamReader, timeout: int = TIMEOUT) -> str:
     msg_bytes = await read_varint_prefixed_bytes(reader, timeout)
     return msg_bytes.decode().rstrip()
+
+
+SIZE_LEN_BYTES = 4
+
+# Fixed-prefixed read/write, used by "/plaintext/2.0.0".
+# Reference: https://github.com/libp2p/go-msgio/blob/d5bbf59d3c4240266b1d2e5df9dc993454c42011/num.go#L11-L33  # noqa: E501  # noqa: E501
+
+
+def encode_fixedint_prefixed(msg_bytes: bytes) -> bytes:
+    len_prefix = len(msg_bytes).to_bytes(SIZE_LEN_BYTES, "big")
+    return len_prefix + msg_bytes
+
+
+async def read_fixedint_prefixed(reader: StreamReader) -> bytes:
+    len_bytes = await reader.read(SIZE_LEN_BYTES)
+    len_int = int.from_bytes(len_bytes, "big")
+    return await reader.read(len_int)