Reducing RAM usage of mbedtls client side

Hi ,

I have a mbedtls based client which is running out of RAM and giving failed to allocate error after the certs are read .
I can see there are 16kbytes of buffers for in and out dynamically allocated.
Is there any way we can get this maximum length down.
In mbedtls documentation I have read " you can change this size if you have control over both server and client "
Questions are:
1- which kind of control required on server to reduce maximum buffer size?
2- Assuming we managed to reduce the size of buffers on client how can we handle incoming data from server larger than maximum size?
I have read documentation on reducing memory usage of mbedtls but didn’t give much detail.
Can anyone help please. Thanks