Request Entity Too Large error

I continue to explore Tryton.
I am trying to build an attach mechanism with a binary field:

device_id = fields.Char('Device ID', size=17, required = True, help = 'Device ID — a 17-chars string');
device_pics = fields.Binary('Pics of the device', file_id = 'device_id',store_prefix='device_', help='Pics of the device');

However, when the image is large enough (mine is 3,4Mb) the user gets the following error:
Reques Entity at Jul 26 16-03-43

Even using the attachment mechanism induce the same error. I think it might be TCP/IP settings, or something else in tryton.conf…
Is there a way to tackle this issue?


Tryton limits the size of the request: Configuration file for Tryton — trytond latest documentation