diff --git a/.vscode/launch.json b/.vscode/launch.json
index b0f99ce6..84701cd6 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -103,6 +103,28 @@
       ],
       "cwd": "${workspaceFolder}/target/debug/"
     },
+    {
+      "type": "lldb",
+      "request": "launch",
+      "name": "Debug veilid-tools unit test",
+      "cargo": {
+        "args": [
+          "test",
+          "--no-run",
+          "--features=rt-tokio",
+          "--manifest-path",
+          "veilid-tools/Cargo.toml"
+        ],
+        "filter": {
+          "kind": "cdylib",
+          "name": "veilid-tools"
+        }
+      },
+      "args": [
+        "${selectedText}"
+      ],
+      "cwd": "${workspaceFolder}/target/debug/"
+    },
     {
       "type": "lldb",
       "request": "launch",
diff --git a/veilid-tools/src/assembly_buffer.rs b/veilid-tools/src/assembly_buffer.rs
index 3bc8abe5..d60e7108 100644
--- a/veilid-tools/src/assembly_buffer.rs
+++ b/veilid-tools/src/assembly_buffer.rs
@@ -282,7 +282,17 @@ impl AssemblyBuffer {
                 let peer_messages = e.get_mut();
 
                 // Insert the fragment and see what comes out
-                peer_messages.insert_fragment(seq, off, len, chunk)
+                let out = peer_messages.insert_fragment(seq, off, len, chunk);
+
+                // If we are returning a message, see if there are any more assemblies for this peer
+                // If not, remove the peer
+                if out.is_some() {
+                    if peer_messages.assemblies.len() == 0 {
+                        e.remove();
+                    }
+                }
+
+                out
             }
             std::collections::hash_map::Entry::Vacant(v) => {
                 // See if we have room for one more
@@ -331,10 +341,10 @@ impl AssemblyBuffer {
         &self,
         data: Vec<u8>,
         remote_addr: SocketAddr,
-        sender: S,
+        mut sender: S,
     ) -> std::io::Result<NetworkResult<()>>
     where
-        S: Fn(Vec<u8>, SocketAddr) -> F,
+        S: FnMut(Vec<u8>, SocketAddr) -> F,
         F: Future<Output = std::io::Result<NetworkResult<()>>>,
     {
         if data.len() > MAX_LEN {
diff --git a/veilid-tools/src/tests/native/test_assembly_buffer.rs b/veilid-tools/src/tests/native/test_assembly_buffer.rs
index 45c448ac..52550dc3 100644
--- a/veilid-tools/src/tests/native/test_assembly_buffer.rs
+++ b/veilid-tools/src/tests/native/test_assembly_buffer.rs
@@ -1,3 +1,5 @@
+use rand::seq::SliceRandom;
+
 use crate::*;
 
 fn random_sockaddr() -> SocketAddr {
@@ -15,6 +17,7 @@ fn random_sockaddr() -> SocketAddr {
 }
 
 pub async fn test_single_out_in() {
+    info!("-- test_single_out_in");
     let assbuf_out = AssemblyBuffer::new();
     let assbuf_in = AssemblyBuffer::new();
     let (net_tx, net_rx) = flume::unbounded();
@@ -30,7 +33,9 @@ pub async fn test_single_out_in() {
     };
 
     for _ in 0..1000 {
-        let message = vec![1u8; 1000];
+        let random_len = (get_random_u32() % 1000) as usize;
+        let mut message = vec![1u8; random_len];
+        random_bytes(&mut message);
         let remote_addr = random_sockaddr();
 
         // Send single message below fragmentation limit
@@ -58,6 +63,344 @@ pub async fn test_single_out_in() {
     assert!(net_rx.is_empty())
 }
 
+pub async fn test_one_frag_out_in() {
+    info!("-- test_one_frag_out_in");
+    let assbuf_out = AssemblyBuffer::new();
+    let assbuf_in = AssemblyBuffer::new();
+    let (net_tx, net_rx) = flume::unbounded();
+    let sender = |framed_chunk: Vec<u8>, remote_addr: SocketAddr| {
+        let net_tx = net_tx.clone();
+        async move {
+            net_tx
+                .send_async((framed_chunk, remote_addr))
+                .await
+                .expect("should send");
+            Ok(NetworkResult::value(()))
+        }
+    };
+
+    let mut all_sent = HashSet::new();
+
+    // Sending
+    println!("sending");
+    for _ in 0..10000 {
+        let random_len = (get_random_u32() % 1000) as usize + 1280;
+        let mut message = vec![1u8; random_len];
+        random_bytes(&mut message);
+        let remote_addr = random_sockaddr();
+
+        // Send single message above fragmentation limit
+        all_sent.insert((message.clone(), remote_addr));
+        assert!(matches!(
+            assbuf_out
+                .split_message(message.clone(), remote_addr, sender)
+                .await,
+            Ok(NetworkResult::Value(()))
+        ));
+    }
+
+    println!("all_sent len={}", all_sent.len());
+
+    println!("fragments sent = {}", net_rx.len());
+
+    drop(net_tx);
+
+    // Receiving
+    println!("receiving");
+
+    while let Ok((frame, r_remote_addr)) = net_rx.recv_async().await {
+        // Send to input
+        let r_message = assbuf_in.insert_frame(&frame, r_remote_addr);
+
+        // We should have gotten the same message
+        if let Some(r_message) = r_message {
+            assert!(all_sent.remove(&(r_message, r_remote_addr)));
+        }
+    }
+    println!("all_sent len={}", all_sent.len());
+
+    // Shoud have dropped no packets
+    assert_eq!(all_sent.len(), 0);
+}
+
+pub async fn test_many_frags_out_in() {
+    info!("-- test_many_frags_out_in");
+    let assbuf_out = AssemblyBuffer::new();
+    let assbuf_in = AssemblyBuffer::new();
+    let (net_tx, net_rx) = flume::unbounded();
+    let sender = |framed_chunk: Vec<u8>, remote_addr: SocketAddr| {
+        let net_tx = net_tx.clone();
+        async move {
+            net_tx
+                .send_async((framed_chunk, remote_addr))
+                .await
+                .expect("should send");
+            Ok(NetworkResult::value(()))
+        }
+    };
+
+    let mut all_sent = HashSet::new();
+
+    // Sending
+    let mut total_sent_size = 0usize;
+    println!("sending");
+    for _ in 0..1000 {
+        let random_len = (get_random_u32() % 65536) as usize;
+        total_sent_size += random_len;
+        let mut message = vec![1u8; random_len];
+        random_bytes(&mut message);
+        let remote_addr = random_sockaddr();
+
+        // Send single message
+        all_sent.insert((message.clone(), remote_addr));
+        assert!(matches!(
+            assbuf_out
+                .split_message(message.clone(), remote_addr, sender)
+                .await,
+            Ok(NetworkResult::Value(()))
+        ));
+    }
+
+    println!("all_sent len={}", all_sent.len());
+    println!("total_sent_size = {}", total_sent_size);
+    println!("fragments sent = {}", net_rx.len());
+
+    drop(net_tx);
+
+    // Receiving
+    println!("receiving");
+
+    while let Ok((frame, r_remote_addr)) = net_rx.recv_async().await {
+        // Send to input
+        let r_message = assbuf_in.insert_frame(&frame, r_remote_addr);
+
+        // We should have gotten the same message
+        if let Some(r_message) = r_message {
+            assert!(all_sent.remove(&(r_message, r_remote_addr)));
+        }
+    }
+    println!("all_sent len={}", all_sent.len());
+
+    // Shoud have dropped no packets
+    assert_eq!(all_sent.len(), 0);
+}
+
+pub async fn test_many_frags_out_in_single_host() {
+    info!("-- test_many_frags_out_in_single_host");
+    let assbuf_out = AssemblyBuffer::new();
+    let assbuf_in = AssemblyBuffer::new();
+    let (net_tx, net_rx) = flume::unbounded();
+    let sender = |framed_chunk: Vec<u8>, remote_addr: SocketAddr| {
+        let net_tx = net_tx.clone();
+        async move {
+            net_tx
+                .send_async((framed_chunk, remote_addr))
+                .await
+                .expect("should send");
+            Ok(NetworkResult::value(()))
+        }
+    };
+
+    let mut all_sent = HashSet::new();
+
+    // Sending
+    let mut total_sent_size = 0usize;
+    println!("sending");
+    for _ in 0..1000 {
+        let random_len = (get_random_u32() % 65536) as usize;
+        total_sent_size += random_len;
+        let mut message = vec![1u8; random_len];
+        random_bytes(&mut message);
+        let remote_addr = SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::new(1, 2, 3, 4), 5678));
+
+        // Send single message
+        all_sent.insert((message.clone(), remote_addr));
+        assert!(matches!(
+            assbuf_out
+                .split_message(message.clone(), remote_addr, sender)
+                .await,
+            Ok(NetworkResult::Value(()))
+        ));
+    }
+
+    println!("all_sent len={}", all_sent.len());
+    println!("total_sent_size = {}", total_sent_size);
+    println!("fragments sent = {}", net_rx.len());
+
+    drop(net_tx);
+
+    // Receiving
+    println!("receiving");
+
+    while let Ok((frame, r_remote_addr)) = net_rx.recv_async().await {
+        // Send to input
+        let r_message = assbuf_in.insert_frame(&frame, r_remote_addr);
+
+        // We should have gotten the same message
+        if let Some(r_message) = r_message {
+            assert!(all_sent.remove(&(r_message, r_remote_addr)));
+        }
+    }
+    println!("all_sent len={}", all_sent.len());
+
+    // Shoud have dropped no packets
+    assert_eq!(all_sent.len(), 0);
+}
+
+pub async fn test_many_frags_with_drops() {
+    info!("-- test_many_frags_with_drops");
+    let assbuf_out = AssemblyBuffer::new();
+    let assbuf_in = AssemblyBuffer::new();
+    let (net_tx, net_rx) = flume::unbounded();
+
+    let first = Arc::new(AtomicBool::new(true));
+
+    let sender = |framed_chunk: Vec<u8>, remote_addr: SocketAddr| {
+        let net_tx = net_tx.clone();
+        let first = first.clone();
+        async move {
+            // Send only first packet, drop rest
+            if first.swap(false, Ordering::Relaxed) {
+                net_tx
+                    .send_async((framed_chunk, remote_addr))
+                    .await
+                    .expect("should send");
+            }
+            Ok(NetworkResult::value(()))
+        }
+    };
+
+    let mut all_sent = HashSet::new();
+
+    // Sending
+    let mut total_sent_size = 0usize;
+    let mut total_fragged = 0usize;
+    println!("sending");
+    for _ in 0..1000 {
+        let random_len = (get_random_u32() % 65536) as usize;
+        if random_len > 1280 {
+            total_fragged += 1;
+        }
+        total_sent_size += random_len;
+        let mut message = vec![1u8; random_len];
+        random_bytes(&mut message);
+        let remote_addr = random_sockaddr();
+
+        // Send single message
+        all_sent.insert((message.clone(), remote_addr));
+        assert!(matches!(
+            assbuf_out
+                .split_message(message.clone(), remote_addr, sender)
+                .await,
+            Ok(NetworkResult::Value(()))
+        ));
+
+        first.store(true, Ordering::Relaxed);
+    }
+
+    println!("all_sent len={}", all_sent.len());
+    println!("total_sent_size = {}", total_sent_size);
+    println!("fragments sent = {}", net_rx.len());
+    println!("total_fragged = {}", total_fragged);
+    drop(net_tx);
+
+    // Receiving
+    println!("receiving");
+
+    while let Ok((frame, r_remote_addr)) = net_rx.recv_async().await {
+        // Send to input
+        let r_message = assbuf_in.insert_frame(&frame, r_remote_addr);
+
+        // We should have gotten the same message
+        if let Some(r_message) = r_message {
+            assert!(all_sent.remove(&(r_message, r_remote_addr)));
+        }
+    }
+    println!("all_sent len={}", all_sent.len());
+
+    // Shoud have dropped all fragged packets
+    assert_eq!(all_sent.len(), total_fragged);
+}
+
+pub async fn test_many_frags_reordered() {
+    info!("-- test_many_frags_reordered");
+    let assbuf_out = AssemblyBuffer::new();
+    let assbuf_in = AssemblyBuffer::new();
+    let (net_tx, net_rx) = flume::unbounded();
+
+    let reorder_buffer = Arc::new(Mutex::new(Vec::new()));
+    let sender = |framed_chunk: Vec<u8>, remote_addr: SocketAddr| {
+        let reorder_buffer = reorder_buffer.clone();
+        async move {
+            reorder_buffer.lock().push((framed_chunk, remote_addr));
+            Ok(NetworkResult::Value(()))
+        }
+    };
+
+    let mut all_sent = HashSet::new();
+
+    // Sending
+    let mut total_sent_size = 0usize;
+    let mut rng = rand::thread_rng();
+    println!("sending");
+    for _ in 0..1000 {
+        let random_len = (get_random_u32() % 65536) as usize;
+        total_sent_size += random_len;
+        let mut message = vec![1u8; random_len];
+        random_bytes(&mut message);
+        let remote_addr = SocketAddr::V4(SocketAddrV4::new(Ipv4Addr::new(1, 2, 3, 4), 5678));
+
+        // Send single message
+        all_sent.insert((message.clone(), remote_addr));
+        assert!(matches!(
+            assbuf_out
+                .split_message(message.clone(), remote_addr, sender)
+                .await,
+            Ok(NetworkResult::Value(()))
+        ));
+
+        // Shuffle fragments
+        let items = {
+            let mut rbinner = reorder_buffer.lock();
+            rbinner.shuffle(&mut rng);
+            let items = rbinner.clone();
+            rbinner.clear();
+            items
+        };
+        for p in items {
+            net_tx.send_async(p).await.expect("should send");
+        }
+    }
+
+    println!("all_sent len={}", all_sent.len());
+    println!("total_sent_size = {}", total_sent_size);
+    println!("fragments sent = {}", net_rx.len());
+
+    drop(net_tx);
+
+    // Receiving
+    println!("receiving");
+
+    while let Ok((frame, r_remote_addr)) = net_rx.recv_async().await {
+        // Send to input
+        let r_message = assbuf_in.insert_frame(&frame, r_remote_addr);
+
+        // We should have gotten the same message
+        if let Some(r_message) = r_message {
+            assert!(all_sent.remove(&(r_message, r_remote_addr)));
+        }
+    }
+    println!("all_sent len={}", all_sent.len());
+
+    // Shoud have dropped no packets
+    assert_eq!(all_sent.len(), 0);
+}
+
 pub async fn test_all() {
     test_single_out_in().await;
+    test_one_frag_out_in().await;
+    test_many_frags_out_in().await;
+    test_many_frags_out_in_single_host().await;
+    test_many_frags_with_drops().await;
+    test_many_frags_reordered().await;
 }