TCPIP_TFTPS_DEFAULT_BLOCK_SIZE Macro

#define TCPIP_TFTPS_DEFAULT_BLOCK_SIZE (32) 

The maximum value for the file name size. Even though the RFC allows blocks of up to 65464 bytes, In practice the limit is set to 1468 bytes: the size of an Ethernet MTU minus the headers of TFTP (4 bytes), UDP (8 bytes) and IP (20 bytes)