Holding 0 on Grandstream 2135 and 2170 results in a + symbol


When I press and hold 0 on my 2135 or my 2170, the phone converts the 0 to a + symbol.

Is there any way to disable this function?


Forgot to mention.

  • symbol is generated when holding 0 on both firmware versions:


I took a look at the template and I do not think I find anything about it


Out of curiosity, why would you need to hold the key down?