diff --git a/src/knx/association_table_object.cpp b/src/knx/association_table_object.cpp
index 926cd9d..ce428ae 100644
--- a/src/knx/association_table_object.cpp
+++ b/src/knx/association_table_object.cpp
@@ -29,7 +29,7 @@ uint16_t AssociationTableObject::entryCount()
     return ntohs(_tableData[0]);
 }
 
-uint16_t AssociationTableObject::operator[](uint16_t idx)
+uint16_t AssociationTableObject::getTSAP(uint16_t idx)
 {
     if (idx < 0 || idx >= entryCount())
         return 0;
@@ -37,6 +37,14 @@ uint16_t AssociationTableObject::operator[](uint16_t idx)
     return ntohs(_tableData[2 * idx + 1]);
 }
 
+uint16_t AssociationTableObject::getASAP(uint16_t idx)
+{
+    if (idx < 0 || idx >= entryCount())
+        return 0;
+
+    return ntohs(_tableData[2 * idx + 2]);
+}
+
 uint8_t* AssociationTableObject::save(uint8_t* buffer)
 {
     return TableObject::save(buffer);
@@ -53,10 +61,10 @@ uint8_t* AssociationTableObject::restore(uint8_t* buffer)
 int32_t AssociationTableObject::translateAsap(uint16_t asap)
 {
     uint16_t entries = entryCount();
-    for (uint16_t i = 0; i < entries * 2; i+=2)
+    for (uint16_t i = 0; i < entries; i++)
     {
-        if (operator[](i + 1) == asap)
-            return operator[](i);
+        if (getASAP(i) == asap)
+            return getTSAP(i);
     }
     return -1;
 }
@@ -97,11 +105,11 @@ int32_t AssociationTableObject::nextAsap(uint16_t tsap, uint16_t& startIdx)
     uint16_t entries = entryCount();
     for (uint16_t i = startIdx; i < entries; i++)
     {
-        startIdx = i;
+        startIdx = i+1;
 
-        if (operator[](i) == tsap)
+        if (getTSAP(i) == tsap)
         {
-            return operator[](i+1);
+            return getASAP(i);
         }
     }
     return -1;
diff --git a/src/knx/association_table_object.h b/src/knx/association_table_object.h
index 7b943ce..b56587c 100644
--- a/src/knx/association_table_object.h
+++ b/src/knx/association_table_object.h
@@ -21,6 +21,7 @@ class AssociationTableObject : public TableObject
 
   private:
     uint16_t entryCount();
-    uint16_t operator[](uint16_t idx);
+    uint16_t getTSAP(uint16_t idx);
+    uint16_t getASAP(uint16_t idx);
     uint16_t* _tableData = 0;
-};
\ No newline at end of file
+};
diff --git a/src/knx/tpuart_data_link_layer.cpp b/src/knx/tpuart_data_link_layer.cpp
index 13b688d..12b45fe 100644
--- a/src/knx/tpuart_data_link_layer.cpp
+++ b/src/knx/tpuart_data_link_layer.cpp
@@ -235,7 +235,7 @@ void TpUartDataLinkLayer::loop()
                 //Destination Address + payload available
                 _xorSum ^= rxByte;
                 //check if echo
-                if (!((buffer[0] ^ _sendBuffer[0]) & ~0x20) && !memcmp(buffer + 2, _sendBuffer + 1, 5))
+                if (!((buffer[0] ^ _sendBuffer[0]) & ~0x20) && !memcmp(buffer + _convert + 1, _sendBuffer + 1, 5))
                 { //ignore repeated bit of control byte
                     _isEcho = true;
                 }