diff --git a/Software/PC_Application/LibreVNA-GUI/Device/device.cpp b/Software/PC_Application/LibreVNA-GUI/Device/device.cpp
index 7ae0426..57e01dd 100644
--- a/Software/PC_Application/LibreVNA-GUI/Device/device.cpp
+++ b/Software/PC_Application/LibreVNA-GUI/Device/device.cpp
@@ -70,6 +70,24 @@ void USBInBuffer::Callback(libusb_transfer *transfer)
     switch(transfer->status) {
     case LIBUSB_TRANSFER_COMPLETED:
         received_size += transfer->actual_length;
+        // Change/insert/delete random data to check the data handling for robustness
+//        srand((unsigned)time(0));
+//        for(unsigned int i=0;i<received_size;i++) {
+//            auto r = rand() % 100;
+//            if(r == 0) {
+//                // modify this byte
+//                buffer[i] = rand() % 256;
+//            } else if(r == 1) {
+//                // insert random byte
+//                memmove(&buffer[i+1], &buffer[i], received_size - i);
+//                buffer[i] = rand() % 256;
+//                received_size++;
+//            } else if(r == 2) {
+//                // remove byte
+//                memmove(&buffer[i], &buffer[i+1], received_size - i - 1);
+//                received_size--;
+//            }
+//        }
 //        qDebug() << transfer->actual_length <<"total:" << received_size;
         inCallback = true;
         emit DataReceived();
diff --git a/Software/VNA_embedded/Application/Communication/Protocol.cpp b/Software/VNA_embedded/Application/Communication/Protocol.cpp
index bfc8912..9a478f5 100644
--- a/Software/VNA_embedded/Application/Communication/Protocol.cpp
+++ b/Software/VNA_embedded/Application/Communication/Protocol.cpp
@@ -52,22 +52,23 @@ uint16_t Protocol::DecodeBuffer(uint8_t *buf, uint16_t len, PacketInfo *info) {
 	}
 
 	/* Evaluate frame size */
-	uint16_t length = *(uint16_t*) &data[1];
-	if(len < length) {
+    uint16_t length = data[1] | ((uint16_t) data[2] << 8);
+
+    if(length > sizeof(PacketInfo) * 2 || length < 8) {
+        // larger than twice the maximum expected packet size or too small, probably an error, ignore
+        info->type = PacketType::None;
+        return 1;
+    }
+
+    if(len < length) {
 		/* The frame payload has not been completely received */
 		info->type = PacketType::None;
 		return data - buf;
 	}
 
-    if(length > sizeof(PacketInfo) * 2) {
-        // larger than twice the maximum expected packet size, probably an error, ignore
-        info->type = PacketType::None;
-        return 1;
-    }
-
 	/* The complete frame has been received, check checksum */
 	auto type = (PacketType) data[3];
-	uint32_t crc = *(uint32_t*) &data[length - 4];
+    uint32_t crc = (uint32_t) data[length-4] | ((uint32_t) data[length-3] << 8) | ((uint32_t) data[length-2] << 16) | ((uint32_t) data[length-1] << 24);
 	if(type != PacketType::VNADatapoint) {
 		uint32_t compare = CRC32(0, data, length - 4);
 		if(crc != compare) {