diff --git a/p25/TrunkPacket.cpp b/p25/TrunkPacket.cpp
index 36af0dab..3924c180 100644
--- a/p25/TrunkPacket.cpp
+++ b/p25/TrunkPacket.cpp
@@ -157,9 +157,9 @@ void TrunkPacket::resetNet()
 /// </summary>
 /// <param name="data">Buffer containing data frame.</param>
 /// <param name="len">Length of data frame.</param>
-/// <param name="mbtData">Flag indicating the data parameter contains MBT data.</param>
+/// <param name="blockData">Flag indicating the data parameter contains raw TSBK data.</param>
 /// <returns></returns>
-bool TrunkPacket::process(uint8_t* data, uint32_t len, bool mbtData)
+bool TrunkPacket::process(uint8_t* data, uint32_t len, bool blockData)
 {
     assert(data != NULL);
 
@@ -167,7 +167,7 @@ bool TrunkPacket::process(uint8_t* data, uint32_t len, bool mbtData)
         return false;
 
     uint8_t duid = 0U;
-    if (!mbtData) {
+    if (!blockData) {
         // Decode the NID
         bool valid = m_p25->m_nid.decode(data + 2U);
 
diff --git a/p25/TrunkPacket.h b/p25/TrunkPacket.h
index 7bbb31e7..8d21e4ff 100644
--- a/p25/TrunkPacket.h
+++ b/p25/TrunkPacket.h
@@ -61,7 +61,7 @@ namespace p25
         void resetNet();
 
         /// <summary>Process a data frame from the RF interface.</summary>
-        bool process(uint8_t* data, uint32_t len, bool mbtData = false);
+        bool process(uint8_t* data, uint32_t len, bool blockData = false);
         /// <summary>Process a data frame from the network.</summary>
         bool processNetwork(uint8_t* data, uint32_t len, lc::LC& control, data::LowSpeedData& lsd, uint8_t& duid);
 
diff --git a/p25/data/DataBlock.cpp b/p25/data/DataBlock.cpp
index 3e777824..e02840ae 100644
--- a/p25/data/DataBlock.cpp
+++ b/p25/data/DataBlock.cpp
@@ -139,6 +139,9 @@ bool DataBlock::decode(const uint8_t* data, const DataHeader header)
             m_data[i] = buffer[i];                                                       // Payload Data
         }
     }
+    else if (m_fmt == PDU_FMT_AMBT) {
+        // ignore AMBT this is handled else where
+    }
     else {
         LogError(LOG_P25, "unknown FMT value in P25_DUID_PDU, fmt = $%02X", m_fmt);
     }
@@ -193,6 +196,9 @@ void DataBlock::encode(uint8_t* data)
 
         m_trellis.encode12(buffer, data);
     }
+    else if (m_fmt == PDU_FMT_AMBT) {
+        // ignore AMBT this is handled else where
+    }
     else {
         LogError(LOG_P25, "unknown FMT value in P25_DUID_PDU, fmt = $%02X", m_fmt);
         return;
@@ -236,7 +242,7 @@ void DataBlock::setData(const uint8_t* buffer)
     if ((m_fmt == PDU_FMT_CONFIRMED) || (m_fmt == PDU_FMT_RSP && m_confirmed)) {
         ::memcpy(m_data, buffer, P25_PDU_CONFIRMED_DATA_LENGTH_BYTES);
     }
-    else if ((m_fmt == PDU_FMT_UNCONFIRMED) || (m_fmt == PDU_FMT_RSP && !m_confirmed)) {
+    else if ((m_fmt == PDU_FMT_UNCONFIRMED) || (m_fmt == PDU_FMT_RSP && !m_confirmed) || (m_fmt == PDU_FMT_AMBT)) {
         ::memcpy(m_data, buffer, P25_PDU_UNCONFIRMED_LENGTH_BYTES);
     }
     else {
@@ -255,7 +261,7 @@ uint32_t DataBlock::getData(uint8_t* buffer) const
         ::memcpy(buffer, m_data, P25_PDU_CONFIRMED_DATA_LENGTH_BYTES);
         return P25_PDU_CONFIRMED_DATA_LENGTH_BYTES;
     } 
-    else if ((m_fmt == PDU_FMT_UNCONFIRMED) || (m_fmt == PDU_FMT_RSP && !m_confirmed)) {
+    else if ((m_fmt == PDU_FMT_UNCONFIRMED) || (m_fmt == PDU_FMT_RSP && !m_confirmed) || (m_fmt == PDU_FMT_AMBT)) {
         ::memcpy(buffer, m_data, P25_PDU_UNCONFIRMED_LENGTH_BYTES);
         return P25_PDU_UNCONFIRMED_LENGTH_BYTES;
     }
diff --git a/p25/data/DataHeader.cpp b/p25/data/DataHeader.cpp
index 1f9f25c3..e41f0995 100644
--- a/p25/data/DataHeader.cpp
+++ b/p25/data/DataHeader.cpp
@@ -127,6 +127,9 @@ bool DataHeader::decode(const uint8_t* data)
         m_n = 0U;
         m_seqNo = 0U;
         m_headerOffset = 0U;
+
+        m_ambtField8 = header[8U];                                              // AMBT Field 8
+        m_ambtField9 = header[9U];                                              // AMBT Field 9
     }
     else {
         m_sync = (header[8U] & 0x80U) == 0x80U;                                 // Re-synchronize Flag
@@ -169,6 +172,8 @@ void DataHeader::encode(uint8_t* data)
 
     if (m_fmt == PDU_FMT_AMBT) {
         header[7U] = (m_ambtOpcode & 0x3FU);                                    // AMBT Opcode
+        header[8U] = m_ambtField8;                                              // AMBT Field 8
+        header[9U] = m_ambtField9;                                              // AMBT Field 9
     }
     else {
         header[7U] = (m_padCount & 0x1FU);                                      // Pad Count
diff --git a/p25/data/DataHeader.h b/p25/data/DataHeader.h
index 084e94bf..80b62159 100644
--- a/p25/data/DataHeader.h
+++ b/p25/data/DataHeader.h
@@ -91,8 +91,13 @@ namespace p25
             __PROPERTY(uint8_t, seqNo, SeqNo);
             /// <summary>Offset of the header.</summary>
             __PROPERTY(uint8_t, headerOffset, HeaderOffset);
+
             /// <summary>Alternate Trunking Block Opcode</summary>
             __PROPERTY(uint8_t, ambtOpcode, AMBTOpcode);
+            /// <summary>Alternate Trunking Block Field 8</summary>
+            __PROPERTY(uint8_t, ambtField8, AMBTField8);
+            /// <summary>Alternate Trunking Block Field 9</summary>
+            __PROPERTY(uint8_t, ambtField9, AMBTField9);
 
         private:
             edac::Trellis m_trellis;