$_defs = array(
'example' => array(
/* type may be 'int', 'string' or 'ostring' -
*
* int - sent as binary
* string - null-terminated string (C-Octet string in the SMPP manual)
* ostring - non-null-terminated string (Octet string)
*/
'type' => 'string',
/* fixed-length size in octets */
'size' => 4,
/* variable-length maximum size in octets. this includes the null
* terminator, if any
*/
'max' => 45
))