I am having problems with SMS messages containing line feeds.
The gateway (firmware wg400-2.5. will respond always with Bad Request error if message contains line feed or any other characters with value below 0x20 (space character).
For example, following REST request will cause Bad Request error:
No matter what encoding is used (%0d%0A, \r\n, ...), the error remains.
According to change log this should work. Quote from log:
wg400-2.3.2.bin
release date: 21/12/2016
*Support CR/LF when sending sms through both HTTP and AMI interfaces;