diff --git a/Cargo.toml b/Cargo.toml
index a38733b..68a2b8e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -54,6 +54,7 @@ serde = ["dep:serde", "spacepackets/serde"]
 [dev-dependencies]
 tempfile = "3"
 rand = "0.8"
+log = "0.4"
 
 [package.metadata.docs.rs]
 all-features = true
diff --git a/examples/python-interop/main.rs b/examples/python-interop/main.rs
index 10c88a6..dbaf0e5 100644
--- a/examples/python-interop/main.rs
+++ b/examples/python-interop/main.rs
@@ -1,6 +1,8 @@
 use std::{
+    fmt::Debug,
     fs::OpenOptions,
-    io::Write,
+    io::{self, ErrorKind, Write},
+    net::{SocketAddr, ToSocketAddrs, UdpSocket},
     sync::{atomic::AtomicBool, mpsc, Arc},
     thread,
     time::Duration,
@@ -8,6 +10,7 @@ use std::{
 
 use cfdp::{
     dest::DestinationHandler,
+    determine_packet_target,
     filestore::NativeFilestore,
     request::{PutRequestOwned, StaticPutRequestCacher},
     source::SourceHandler,
@@ -15,8 +18,9 @@ use cfdp::{
     EntityType, IndicationConfig, LocalEntityConfig, PduWithInfo, RemoteEntityConfig,
     StdCheckTimerCreator, TransactionId, UserFaultHookProvider,
 };
+use log::{info, warn};
 use spacepackets::{
-    cfdp::{ChecksumType, ConditionCode, TransmissionMode},
+    cfdp::{pdu::PduError, ChecksumType, ConditionCode, TransmissionMode},
     seq_count::SeqCountProviderSyncU16,
     util::UnsignedByteFieldU16,
 };
@@ -155,6 +159,90 @@ impl CfdpUser for ExampleCfdpUser {
     }
 }
 
+pub struct UdpServer {
+    pub socket: UdpSocket,
+    recv_buf: Vec<u8>,
+    sender_addr: Option<SocketAddr>,
+    src_tx: mpsc::SyncSender<Vec<u8>>,
+    dest_tx: mpsc::SyncSender<Vec<u8>>,
+    tm_rx: mpsc::Receiver<Vec<u8>>,
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum UdpServerError {
+    #[error("nothing was received")]
+    NothingReceived,
+    #[error(transparent)]
+    Io(#[from] io::Error),
+    #[error("pdu error: {0}")]
+    Pdu(#[from] PduError),
+    #[error("send error")]
+    Send,
+}
+
+impl UdpServer {
+    pub fn new<A: ToSocketAddrs>(
+        addr: A,
+        max_recv_size: usize,
+        src_tx: mpsc::SyncSender<Vec<u8>>,
+        dest_tx: mpsc::SyncSender<Vec<u8>>,
+        tm_rx: mpsc::Receiver<Vec<u8>>,
+    ) -> Result<Self, io::Error> {
+        let server = Self {
+            socket: UdpSocket::bind(addr)?,
+            recv_buf: vec![0; max_recv_size],
+            tm_rx,
+            src_tx,
+            dest_tx,
+            sender_addr: None,
+        };
+        server.socket.set_nonblocking(true)?;
+        Ok(server)
+    }
+
+    pub fn try_recv_tc(&mut self) -> Result<(usize, SocketAddr), UdpServerError> {
+        let res = match self.socket.recv_from(&mut self.recv_buf) {
+            Ok(res) => res,
+            Err(e) => {
+                return if e.kind() == ErrorKind::WouldBlock || e.kind() == ErrorKind::TimedOut {
+                    Err(UdpServerError::NothingReceived)
+                } else {
+                    Err(e.into())
+                }
+            }
+        };
+        let (num_bytes, from) = res;
+        self.sender_addr = Some(from);
+        let packet_target = determine_packet_target(&self.recv_buf)?;
+        match packet_target {
+            cfdp::PacketTarget::SourceEntity => {
+                self.src_tx
+                    .send(self.recv_buf[0..num_bytes].to_vec())
+                    .map_err(|_| UdpServerError::Send)?;
+            }
+            cfdp::PacketTarget::DestEntity => {
+                self.dest_tx
+                    .send(self.recv_buf[0..num_bytes].to_vec())
+                    .map_err(|_| UdpServerError::Send)?;
+            }
+        }
+        Ok(res)
+    }
+
+    pub fn send_tm(&mut self, socket: &UdpSocket, recv_addr: &SocketAddr) {
+        while let Ok(tm) = self.tm_rx.try_recv() {
+            let result = socket.send_to(&tm, recv_addr);
+            if let Err(e) = result {
+                warn!("Sending TM with UDP socket failed: {e}")
+            }
+        }
+    }
+
+    pub fn last_sender(&self) -> Option<SocketAddr> {
+        self.sender_addr
+    }
+}
+
 fn main() {
     // Simplified event handling using atomic signals.
     let stop_signal_source = Arc::new(AtomicBool::new(false));
diff --git a/src/dest.rs b/src/dest.rs
index 7657442..3d3415e 100644
--- a/src/dest.rs
+++ b/src/dest.rs
@@ -860,7 +860,11 @@ mod tests {
     use spacepackets::{
         cfdp::{
             lv::Lv,
-            pdu::{finished::FinishedPduReader, metadata::MetadataPduCreator, WritablePduPacket},
+            pdu::{
+                finished::{self, FinishedPduReader},
+                metadata::MetadataPduCreator,
+                WritablePduPacket,
+            },
             ChecksumType, TransmissionMode,
         },
         util::{UbfU16, UnsignedByteFieldU16},
@@ -1565,6 +1569,13 @@ mod tests {
             Some(FileDirectiveType::FinishedPdu)
         );
         let finished_pdu = FinishedPduReader::from_bytes(&sent_pdu.raw_pdu).unwrap();
+        assert_eq!(finished_pdu.file_status(), FileStatus::Retained);
+        assert_eq!(
+            finished_pdu.condition_code(),
+            ConditionCode::CheckLimitReached
+        );
+        assert_eq!(finished_pdu.delivery_code(), DeliveryCode::Incomplete);
         assert!(tb.handler.pdu_sender.queue_empty());
+        tb.expected_full_data = faulty_file_data.to_vec();
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index 84f9428..3a56dce 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -724,19 +724,20 @@ impl PduProvider for DummyPduProvider {
 pub struct PacketInfo<'raw_packet> {
     pdu_type: PduType,
     file_directive_type: Option<FileDirectiveType>,
-    //target: PacketTarget,
     raw_packet: &'raw_packet [u8],
 }
 
-pub fn determine_packet_target(
-    file_directive_type: Option<FileDirectiveType>,
-    raw_pdu: &[u8],
-) -> Result<PacketTarget, PduError> {
-    if file_directive_type.is_none() {
+pub fn determine_packet_target(raw_pdu: &[u8]) -> Result<PacketTarget, PduError> {
+    let (header, header_len) = PduHeader::from_bytes(raw_pdu)?;
+    if header.pdu_type() == PduType::FileData {
         return Ok(PacketTarget::DestEntity);
     }
-    let (_, header_len) = PduHeader::from_bytes(raw_pdu)?;
-    let file_directive_type = file_directive_type.unwrap();
+    let file_directive_type = FileDirectiveType::try_from(raw_pdu[header_len]).map_err(|_| {
+        PduError::InvalidDirectiveType {
+            found: raw_pdu[header_len],
+            expected: None,
+        }
+    })?;
     let packet_target =
         match file_directive_type {
             // Section c) of 4.5.3: These PDUs should always be targeted towards the file sender a.k.a.
@@ -823,7 +824,7 @@ impl PduProvider for PacketInfo<'_> {
     }
 
     fn packet_target(&self) -> Result<PacketTarget, PduError> {
-        determine_packet_target(self.file_directive_type, self.raw_packet)
+        determine_packet_target(self.raw_packet)
     }
 }
 
@@ -870,7 +871,7 @@ pub mod alloc_mod {
         }
 
         fn packet_target(&self) -> Result<PacketTarget, PduError> {
-            determine_packet_target(self.file_directive_type, &self.pdu)
+            determine_packet_target(&self.pdu)
         }
     }
 }