In my country there are 3 mobile service operators, and when I send one SMS from two of they, the Gammu daemon table inbox shows the TextDecoded field separated in 2 or 3 parts, and that tuples show a some kind of numeration in the UDH field, but just when the SMS text is too long, like more of 130 characters, something like this:
+-------------------------------+
| *UDH* | *Text* |
+-------------------------------+
| 050003B90301 | Hi my name is A|
+-------------------------------+
| 050003B90302 | rmin and I wan |
+-------------------------------+
| 050003B90303 | t be your frien|
+-------------------------------+
I don't know if exist a configuration for correct that. I'm working with MySQL.