where is CONFIG_UDP_DATA_UPLOAD_SIZE_BYTES defined

[paul_tanner]

I am working with the udp example in nrfConnect for the nRF9160

I see that CONFIG_UDP_DATA_UPLOAD_SIZE_BYTES has the value of 10 (bytes of payload).  However, I do not see where this is defined.  I would like to override it to about 30 bytes but do not want to overwrite anything.

BTW. The udp header size is 28 bytes.  Seems like a large overhead. Where could I find a reference for what the header contains?

Thx.

[tracking]

Hello 

where I can find Kconfig or how I can modify?