diff --git a/exercises/204_established_identities/src/main.cpp b/exercises/204_established_identities/src/main.cpp
index 4ca6ec1..dab683d 100644
--- a/exercises/204_established_identities/src/main.cpp
+++ b/exercises/204_established_identities/src/main.cpp
@@ -703,6 +703,14 @@ static String parse_recipient_label(const String& text) {
 }
 
 static void attach_link_callbacks(RNS::Link& link) {
+  if (link) {
+    Serial.printf("APP LINK CALLBACKS: attach hash=%s status=%u initiator=%u\r\n",
+                  link.hash().toHex().c_str(),
+                  (unsigned)link.status(),
+                  link.initiator() ? 1U : 0U);
+  } else {
+    Serial.println("APP LINK CALLBACKS: attach skipped null link");
+  }
   link.set_packet_callback(on_link_packet);
   link.set_link_closed_callback(on_link_closed);
 }
@@ -716,6 +724,14 @@ static void on_link_packet(const RNS::Bytes& data, const RNS::Packet& packet) {
   String text = data.toString().c_str();
   String sender = parse_sender_label(text);
   String recipient = parse_recipient_label(text);
+  Serial.printf("APP RX LINK ENTER: link=%s status=%u initiator=%u peer_index=%d sender=%s recipient=%s text=%s\r\n",
+                packet.link() ? packet.link().hash().toHex().c_str() : "(none)",
+                packet.link() ? (unsigned)packet.link().status() : 255U,
+                packet.link() && packet.link().initiator() ? 1U : 0U,
+                peer_index,
+                sender.c_str(),
+                recipient.c_str(),
+                text.c_str());
   if (sender == NODE_LABEL || (recipient.length() > 0 && recipient != NODE_LABEL)) {
     Serial.printf("RX LINK ignored: self_or_wrong_recipient text=%s\r\n", text.c_str());
     return;
@@ -795,6 +811,11 @@ static void on_link_closed(RNS::Link& link) {
 
 static void on_outbound_link_established(RNS::Link& link) {
   int peer_index = find_peer_by_link_hash(link.hash());
+  Serial.printf("APP LINK ESTABLISHED CB: direction=outbound hash=%s status=%u initiator=%u peer_index=%d\r\n",
+                link.hash().toHex().c_str(),
+                (unsigned)link.status(),
+                link.initiator() ? 1U : 0U,
+                peer_index);
   if (peer_index >= 0) {
     peers[peer_index].outbound_link = link;
     attach_link_callbacks(peers[peer_index].outbound_link);
@@ -817,6 +838,11 @@ static void on_inbound_link_established(RNS::Link& link) {
   if (peer_index < 0) {
     peer_index = first_free_peer_slot();
   }
+  Serial.printf("APP LINK ESTABLISHED CB: direction=inbound hash=%s status=%u initiator=%u peer_index=%d\r\n",
+                link.hash().toHex().c_str(),
+                (unsigned)link.status(),
+                link.initiator() ? 1U : 0U,
+                peer_index);
   if (peer_index >= 0) {
     peers[peer_index].inbound_link = link;
     attach_link_callbacks(peers[peer_index].inbound_link);
@@ -942,6 +968,12 @@ static void maybe_open_link(const DateTime& rtc_now, bool have_rtc_now) {
       continue;
     }
     if (peer.outbound_active || (peer.outbound_link && peer.outbound_link.status() == RNS::Type::Link::ACTIVE)) {
+      if (!peer.outbound_active) {
+        Serial.printf("APP LINK STATE: outbound already active peer=%s hash=%s status=%u\r\n",
+                      peer.label.c_str(),
+                      peer.outbound_link.hash().toHex().c_str(),
+                      (unsigned)peer.outbound_link.status());
+      }
       peer.outbound_active = true;
       continue;
     }
@@ -1108,13 +1140,27 @@ void loop() {
         link = &peer.inbound_link;
       }
       if (!link) {
+        Serial.printf("TX LINK SKIP: peer=%s outbound=%u outbound_status=%u inbound=%u inbound_status=%u attempted=%u active_out=%u active_in=%u\r\n",
+                      peer.label.c_str(),
+                      peer.outbound_link ? 1U : 0U,
+                      peer.outbound_link ? (unsigned)peer.outbound_link.status() : 255U,
+                      peer.inbound_link ? 1U : 0U,
+                      peer.inbound_link ? (unsigned)peer.inbound_link.status() : 255U,
+                      peer.outbound_attempted ? 1U : 0U,
+                      peer.outbound_active ? 1U : 0U,
+                      peer.inbound_active ? 1U : 0U);
         continue;
       }
 
       peer.last_tx_second = rtc_now.second;
       peer.last_tx_ms = now;
       String message = String("Hi from ") + NODE_LABEL + " iter=" + String(peer.tx_iter++) + " to=" + peer.label;
-      Serial.printf("TX LINK: %s\r\n", message.c_str());
+      Serial.printf("TX LINK: %s via=%s hash=%s status=%u since_open=%u\r\n",
+                    message.c_str(),
+                    link == &peer.outbound_link ? "outbound" : "inbound",
+                    link->hash().toHex().c_str(),
+                    (unsigned)link->status(),
+                    (unsigned)peer.tx_since_link_open);
       show_status("TX LINK", peer.label.c_str(), message.c_str());
       RNS::Packet(*link, RNS::bytesFromString(message.c_str())).send();
       ++peer.tx_since_link_open;