Yes, thanks. But that's exactly what I am doing. And my first reply, after the IMEi works just fine. And the tracker starts to send the AVL data.
And the count of the elements I get with the AVL data matches exactly the "Number Of Data 1". And I return exactly this count of data with the pack('N', $x) function. $x, is the number of data.
I reduced the code that way, that I, right after I read the AVL data, fetched the "Number Of Data 1" from the data and directly return it with pack('N', ...). So, no any other foreign code from me was included in any calculation or something. But the tracker still sends more and more than and never got "reset". It sends same data with same timestamp again and again.