diff --git a/configs/fne-config.example.yml b/configs/fne-config.example.yml
index 95ff4dcf..f59fd91c 100644
--- a/configs/fne-config.example.yml
+++ b/configs/fne-config.example.yml
@@ -68,6 +68,9 @@ master:
     # Flag indicating whether or not a parrot TG call will generate a grant demand.
     parrotGrantDemand: true
 
+    # Flag indicating whether or not a P25 ADJ_STS_BCAST will pass to connected external peers.
+    disallowP25AdjStsBcast: false
+
     #
     # Talkgroup Rules Configuration
     #
@@ -78,7 +81,7 @@ master:
         time: 30
 
 #
-# Peers
+# External Peers
 #
 peers:
     - name: EXAMPLEPEER
diff --git a/src/fne/HostFNE.cpp b/src/fne/HostFNE.cpp
index 2cd131f2..9f8a6b63 100644
--- a/src/fne/HostFNE.cpp
+++ b/src/fne/HostFNE.cpp
@@ -448,6 +448,7 @@ bool HostFNE::createMasterNetwork()
     // initialize networking
     m_network = new FNENetwork(this, address, port, id, password, debug, verbose, reportPeerPing, m_dmrEnabled, m_p25Enabled, m_nxdnEnabled, 
         parrotDelay, parrotGrantDemand, m_allowActivityTransfer, m_allowDiagnosticTransfer, m_pingTime, m_updateLookupTime);
+    m_network->setOptions(masterConf, true);
 
     m_network->setLookups(m_ridLookup, m_tidLookup);
 
diff --git a/src/fne/network/FNENetwork.cpp b/src/fne/network/FNENetwork.cpp
index 0c87c5b5..b4a8a7a1 100644
--- a/src/fne/network/FNENetwork.cpp
+++ b/src/fne/network/FNENetwork.cpp
@@ -77,6 +77,7 @@ FNENetwork::FNENetwork(HostFNE* host, const std::string& address, uint16_t port,
     m_updateLookupTimer(1000U, (updateLookupTime * 60U)),
     m_forceListUpdate(false),
     m_callInProgress(false),
+    m_disallowP25AdjStsBcast(false),
     m_reportPeerPing(reportPeerPing),
     m_verbose(verbose)
 {
@@ -100,6 +101,20 @@ FNENetwork::~FNENetwork()
     delete m_tagNXDN;
 }
 
+/// <summary>
+/// Helper to set configuration options.
+/// </summary>
+/// <param name="conf">Instance of the yaml::Node class.</param>
+/// <param name="printOptions"></param>
+void FNENetwork::setOptions(yaml::Node& conf, bool printOptions)
+{
+    m_disallowP25AdjStsBcast = conf["disallowP25AdjStsBcast"].as<bool>(false);
+
+    if (printOptions) {
+        LogInfo("    Disable P25 ADJ_STS_BCAST to external peers: %s", m_disallowP25AdjStsBcast ? "yes" : "no");
+    }
+}
+
 /// <summary>
 /// Sets the instances of the Radio ID and Talkgroup Rules lookup tables.
 /// </summary>
@@ -322,17 +337,15 @@ void FNENetwork::clock(uint32_t ms)
                     // the login sequence
                     if (peerId > 0 && (m_peers.find(peerId) != m_peers.end())) {
                         FNEPeerConnection* connection = m_peers[peerId];
-                        LogMessage(LOG_NET, "PEER %u was RPTL NAKed cleaning up peer connection", peerId);
+                        LogMessage(LOG_NET, "PEER %u was RPTL NAKed, cleaning up peer connection, connectionState = %u", peerId, connection->connectionState());
                         if (connection != nullptr) {
-                            if (connection->connectionState() != NET_STAT_RUNNING) {
-                                if (erasePeer(peerId)) {
-                                    delete connection;
-                                }
+                            if (erasePeer(peerId)) {
+                                delete connection;
                             }
                         } else {
                             erasePeer(peerId);
                             if (m_verbose) {
-                                LogWarning(LOG_NET, "PEER %u was RPTL NAKed while having no connection?", peerId);
+                                LogWarning(LOG_NET, "PEER %u was RPTL NAKed while having no connection?, connectionState = %u", peerId, connection->connectionState());
                             }
                         }
                     }
diff --git a/src/fne/network/FNENetwork.h b/src/fne/network/FNENetwork.h
index a40ec28f..58b7c283 100644
--- a/src/fne/network/FNENetwork.h
+++ b/src/fne/network/FNENetwork.h
@@ -146,6 +146,9 @@ namespace network
         /// <summary>Finalizes a instance of the FNENetwork class.</summary>
         ~FNENetwork() override;
 
+        /// <summary>Helper to set configuration options.</summary>
+        void setOptions(yaml::Node& conf, bool printOptions);
+
         /// <summary>Gets the current status of the network.</summary>
         NET_CONN_STATUS getStatus() { return m_status; }
 
@@ -209,6 +212,8 @@ namespace network
         bool m_forceListUpdate;
         bool m_callInProgress;
 
+        bool m_disallowP25AdjStsBcast;
+
         bool m_reportPeerPing;
         bool m_verbose;
 
diff --git a/src/fne/network/fne/TagDMRData.cpp b/src/fne/network/fne/TagDMRData.cpp
index 2c7b4eb5..a4ca0c96 100644
--- a/src/fne/network/fne/TagDMRData.cpp
+++ b/src/fne/network/fne/TagDMRData.cpp
@@ -120,6 +120,11 @@ bool TagDMRData::processFrame(const uint8_t* data, uint32_t len, uint32_t peerId
 
         // is this the end of the call stream?
         if (dataSync && (dataType == DT_TERMINATOR_WITH_LC)) {
+            if (srcId == 0U && dstId == 0U) {
+                LogWarning(LOG_NET, "DMR, invalid TERMINATOR, peer = %u, srcId = %u, dstId = %u, streamId = %u", peerId, srcId, dstId, streamId);
+                return false;
+            }
+
             RxStatus status;
             auto it = std::find_if(m_status.begin(), m_status.end(), [&](StatusMapPair x) { return (x.second.dstId == dstId && x.second.slotNo == slotNo); });
             if (it == m_status.end()) {
@@ -153,6 +158,11 @@ bool TagDMRData::processFrame(const uint8_t* data, uint32_t len, uint32_t peerId
 
         // is this a new call stream?
         if (dataSync && (dataType == DT_VOICE_LC_HEADER)) {
+            if (srcId == 0U && dstId == 0U) {
+                LogWarning(LOG_NET, "DMR, invalid call, peer = %u, srcId = %u, dstId = %u, streamId = %u", peerId, srcId, dstId, streamId);
+                return false;
+            }
+
             auto it = std::find_if(m_status.begin(), m_status.end(), [&](StatusMapPair x) { return (x.second.dstId == dstId && x.second.slotNo == slotNo); });
             if (it != m_status.end()) {
                 RxStatus status = it->second;
@@ -487,6 +497,9 @@ bool TagDMRData::validate(uint32_t peerId, data::Data& data, uint32_t streamId)
     // is this a group call?
     if (data.getDataType() == FLCO_GROUP) {
         lookups::TalkgroupRuleGroupVoice tg = m_network->m_tidLookup->find(data.getDstId());
+        if (tg.isInvalid()) {
+            return false;
+        }
 
         // check the DMR slot number
         if (tg.source().tgSlot() != data.getSlotNo()) {
diff --git a/src/fne/network/fne/TagNXDNData.cpp b/src/fne/network/fne/TagNXDNData.cpp
index db63f689..756cae4c 100644
--- a/src/fne/network/fne/TagNXDNData.cpp
+++ b/src/fne/network/fne/TagNXDNData.cpp
@@ -99,6 +99,11 @@ bool TagNXDNData::processFrame(const uint8_t* data, uint32_t len, uint32_t peerI
              messageType == RTCH_MESSAGE_TYPE_DCALL_DATA)) {
             // is this the end of the call stream?
             if (messageType == RTCH_MESSAGE_TYPE_TX_REL || messageType == RTCH_MESSAGE_TYPE_TX_REL_EX) {
+                if (srcId == 0U && dstId == 0U) {
+                    LogWarning(LOG_NET, "NXDN, invalid TX_REL, peer = %u, srcId = %u, dstId = %u, streamId = %u", peerId, srcId, dstId, streamId);
+                    return false;
+                }
+
                 RxStatus status = m_status[dstId];
                 uint64_t duration = hrc::diff(pktTime, status.callStartTime);
 
@@ -123,6 +128,11 @@ bool TagNXDNData::processFrame(const uint8_t* data, uint32_t len, uint32_t peerI
 
             // is this a new call stream?
             if ((messageType != RTCH_MESSAGE_TYPE_TX_REL && messageType != RTCH_MESSAGE_TYPE_TX_REL_EX)) {
+                if (srcId == 0U && dstId == 0U) {
+                    LogWarning(LOG_NET, "NXDN, invalid call, peer = %u, srcId = %u, dstId = %u, streamId = %u", peerId, srcId, dstId, streamId);
+                    return false;
+                }
+
                 auto it = std::find_if(m_status.begin(), m_status.end(), [&](StatusMapPair x) { return x.second.dstId == dstId; });
                 if (it != m_status.end()) {
                     RxStatus status = m_status[dstId];
@@ -410,6 +420,12 @@ bool TagNXDNData::validate(uint32_t peerId, lc::RTCH& lc, uint8_t messageType, u
     }
 
     lookups::TalkgroupRuleGroupVoice tg = m_network->m_tidLookup->find(lc.getDstId());
+
+    // check TGID validity
+    if (tg.isInvalid()) {
+        return false;
+    }
+
     if (!tg.config().active()) {
         return false;
     }
diff --git a/src/fne/network/fne/TagP25Data.cpp b/src/fne/network/fne/TagP25Data.cpp
index d7484234..b310ae72 100644
--- a/src/fne/network/fne/TagP25Data.cpp
+++ b/src/fne/network/fne/TagP25Data.cpp
@@ -130,8 +130,20 @@ bool TagP25Data::processFrame(const uint8_t* data, uint32_t len, uint32_t peerId
     lsd.setLSD1(lsd1);
     lsd.setLSD2(lsd2);
 
+    uint32_t frameLength = buffer[23U];
+
+    // process a TSBK out into a class literal if possible
+    std::unique_ptr<lc::TSBK> tsbk;
+    if (duid == P25_DUID_TSDU) {
+        UInt8Array data = std::unique_ptr<uint8_t[]>(new uint8_t[frameLength]);
+        ::memset(data.get(), 0x00U, frameLength);
+        ::memcpy(data.get(), buffer + 24U, frameLength);
+
+        tsbk = lc::tsbk::TSBKFactory::createTSBK(data.get());
+    }
+
     // is the stream valid?
-    if (validate(peerId, control, duid, streamId)) {
+    if (validate(peerId, control, duid, tsbk.get(), streamId)) {
         // is this peer ignored?
         if (!isPeerPermitted(peerId, control, duid, streamId)) {
             return false;
@@ -141,6 +153,11 @@ bool TagP25Data::processFrame(const uint8_t* data, uint32_t len, uint32_t peerId
         if (duid != P25_DUID_TSDU && duid != P25_DUID_PDU) {
             // is this the end of the call stream?
             if ((duid == P25_DUID_TDU) || (duid == P25_DUID_TDULC)) {
+                if (srcId == 0U && dstId == 0U) {
+                    LogWarning(LOG_NET, "P25, invalid TDU, peer = %u, srcId = %u, dstId = %u, streamId = %u", peerId, srcId, dstId, streamId);
+                    return false;
+                }
+
                 RxStatus status = m_status[dstId];
                 uint64_t duration = hrc::diff(pktTime, status.callStartTime);
 
@@ -175,6 +192,11 @@ bool TagP25Data::processFrame(const uint8_t* data, uint32_t len, uint32_t peerId
 
             // is this a new call stream?
             if ((duid != P25_DUID_TDU) && (duid != P25_DUID_TDULC)) {
+                if (srcId == 0U && dstId == 0U) {
+                    LogWarning(LOG_NET, "P25, invalid call, peer = %u, srcId = %u, dstId = %u, streamId = %u", peerId, srcId, dstId, streamId);
+                    return false;
+                }
+
                 auto it = std::find_if(m_status.begin(), m_status.end(), [&](StatusMapPair x) { return x.second.dstId == dstId; });
                 if (it != m_status.end()) {
                     RxStatus status = m_status[dstId];
@@ -270,10 +292,13 @@ bool TagP25Data::processFrame(const uint8_t* data, uint32_t len, uint32_t peerId
                     // perform TGID route rewrites if configured
                     routeRewrite(outboundPeerBuffer, dstPeerId, duid, dstId);
 
-                    peer.second->writeMaster({ NET_FUNC_PROTOCOL, NET_PROTOCOL_SUBFUNC_P25 }, outboundPeerBuffer, len, pktSeq, streamId);
-                    if (m_network->m_debug) {
-                        LogDebug(LOG_NET, "P25, srcPeer = %u, dstPeer = %u, duid = $%02X, lco = $%02X, MFId = $%02X, srcId = %u, dstId = %u, len = %u, pktSeq = %u, streamId = %u", 
-                            peerId, dstPeerId, duid, lco, MFId, srcId, dstId, len, pktSeq, streamId);
+                    // process TSDUs going to external peers
+                    if (processTSDUToExternal(outboundPeerBuffer, dstPeerId, duid)) {
+                        peer.second->writeMaster({ NET_FUNC_PROTOCOL, NET_PROTOCOL_SUBFUNC_P25 }, outboundPeerBuffer, len, pktSeq, streamId);
+                        if (m_network->m_debug) {
+                            LogDebug(LOG_NET, "P25, srcPeer = %u, dstPeer = %u, duid = $%02X, lco = $%02X, MFId = $%02X, srcId = %u, dstId = %u, len = %u, pktSeq = %u, streamId = %u", 
+                                peerId, dstPeerId, duid, lco, MFId, srcId, dstId, len, pktSeq, streamId);
+                        }
                     }
 
                     if (!m_network->m_callInProgress)
@@ -331,7 +356,7 @@ void TagP25Data::playbackParrot()
             m_parrotFirstFrame = false;
         }
 
-        // repeat traffic to the connected peersmutations
+        // repeat traffic to the connected peers
         for (auto peer : m_network->m_peers) {
             m_network->writePeer(peer.first, { NET_FUNC_PROTOCOL, NET_PROTOCOL_SUBFUNC_P25 }, std::get<0>(pkt), std::get<1>(pkt), std::get<2>(pkt), std::get<3>(pkt), false);
             if (m_network->m_debug) {
@@ -450,6 +475,50 @@ bool TagP25Data::peerRewrite(uint32_t peerId, uint32_t& dstId, bool outbound)
     return false;
 }
 
+/// <summary>
+/// Helper to process TSDUs being passed to an external peer.
+/// </summary>
+/// <param name="buffer"></param>
+/// <param name="peerId">Peer ID</param>
+/// <param name="duid"></param>
+bool TagP25Data::processTSDUToExternal(uint8_t* buffer, uint32_t peerId, uint8_t duid)
+{
+    // are we receiving a TSDU?
+    if (duid == P25_DUID_TSDU) {
+        uint32_t frameLength = buffer[23U];
+
+        UInt8Array data = std::unique_ptr<uint8_t[]>(new uint8_t[frameLength]);
+        ::memset(data.get(), 0x00U, frameLength);
+        ::memcpy(data.get(), buffer + 24U, frameLength);
+
+        std::unique_ptr<lc::TSBK> tsbk = lc::tsbk::TSBKFactory::createTSBK(data.get());
+        if (tsbk != nullptr) {
+            // handle standard P25 reference opcodes
+            switch (tsbk->getLCO()) {
+            case TSBK_OSP_ADJ_STS_BCAST:
+                {
+                    lc::tsbk::OSP_ADJ_STS_BCAST* osp = static_cast<lc::tsbk::OSP_ADJ_STS_BCAST*>(tsbk.get());
+
+                    if (m_network->m_verbose) {
+                        LogMessage(LOG_NET, P25_TSDU_STR ", %s, sysId = $%03X, rfss = $%02X, site = $%02X, chId = %u, chNo = %u, svcClass = $%02X", tsbk->toString().c_str(),
+                            osp->getAdjSiteSysId(), osp->getAdjSiteRFSSId(), osp->getAdjSiteId(), osp->getAdjSiteChnId(), osp->getAdjSiteChnNo(), osp->getAdjSiteSvcClass());
+                    }
+
+                    if (m_network->m_disallowP25AdjStsBcast) {
+                        LogWarning(LOG_NET, "PEER %u, passing ADJ_STS_BCAST to external peers is prohibited, dropping", peerId);
+                        return false;
+                    }
+                }
+                break;
+            default:
+                break;
+            }
+        }
+    }
+
+    return true;
+}
+
 /// <summary>
 /// Helper to determine if the peer is permitted for traffic.
 /// </summary>
@@ -513,9 +582,10 @@ bool TagP25Data::isPeerPermitted(uint32_t peerId, lc::LC& control, uint8_t duid,
 /// <param name="peerId">Peer ID</param>
 /// <param name="control"></param>
 /// <param name="duid"></param>
+/// <param name="tsbk"></param>
 /// <param name="streamId">Stream ID</param>
 /// <returns></returns>
-bool TagP25Data::validate(uint32_t peerId, lc::LC& control, uint8_t duid, uint32_t streamId)
+bool TagP25Data::validate(uint32_t peerId, lc::LC& control, uint8_t duid, const p25::lc::TSBK* tsbk, uint32_t streamId)
 {
     // is the source ID a blacklisted ID?
     lookups::RadioId rid = m_network->m_ridLookup->find(control.getSrcId());
@@ -525,8 +595,8 @@ bool TagP25Data::validate(uint32_t peerId, lc::LC& control, uint8_t duid, uint32
         }
     }
 
-    // always validate a TSDU or PDU if the source is valid
-    if (duid == P25_DUID_TSDU || duid == P25_DUID_PDU)
+    // always validate a PDU if the source is valid
+    if (duid == P25_DUID_PDU)
         return true;
 
     // always validate a terminator if the source is valid
@@ -546,7 +616,37 @@ bool TagP25Data::validate(uint32_t peerId, lc::LC& control, uint8_t duid, uint32
         return true;
     }
 
+    // always validate a TSDU or PDU if the source is valid
+    if (duid == P25_DUID_TSDU) {
+        if (tsbk != nullptr) {
+            // handle standard P25 reference opcodes
+            switch (tsbk->getLCO()) {
+                case TSBK_IOSP_GRP_VCH:
+                {
+                    lookups::TalkgroupRuleGroupVoice tg = m_network->m_tidLookup->find(tsbk->getDstId());
+
+                    // check TGID validity
+                    if (tg.isInvalid()) {
+                        return false;
+                    }
+
+                    if (!tg.config().active()) {
+                        return false;
+                    }
+                }
+                break;
+            }
+        }
+
+        return true;
+    }
+
+    // check TGID validity
     lookups::TalkgroupRuleGroupVoice tg = m_network->m_tidLookup->find(control.getDstId());
+    if (tg.isInvalid()) {
+        return false;
+    }
+
     if (!tg.config().active()) {
         return false;
     }
diff --git a/src/fne/network/fne/TagP25Data.h b/src/fne/network/fne/TagP25Data.h
index 3cdd9341..1e8a2a89 100644
--- a/src/fne/network/fne/TagP25Data.h
+++ b/src/fne/network/fne/TagP25Data.h
@@ -75,10 +75,13 @@ namespace network
             /// <summary>Helper to route rewrite destination ID.</summary>
             bool peerRewrite(uint32_t peerId, uint32_t& dstId, bool outbound = true);
 
+            /// <summary>Helper to process TSDUs being passed to an external peer.</summary>
+            bool processTSDUToExternal(uint8_t* buffer, uint32_t peerId, uint8_t duid);
+
             /// <summary>Helper to determine if the peer is permitted for traffic.</summary>
             bool isPeerPermitted(uint32_t peerId, p25::lc::LC& control, uint8_t duid, uint32_t streamId);
             /// <summary>Helper to validate the P25 call stream.</summary>
-            bool validate(uint32_t peerId, p25::lc::LC& control, uint8_t duid, uint32_t streamId);
+            bool validate(uint32_t peerId, p25::lc::LC& control, uint8_t duid, const p25::lc::TSBK* tsbk, uint32_t streamId);
         };
     } // namespace fne
 } // namespace network