TCPIP_UDP_SOCKET_DEFAULT_TX_SIZE Macro

#define TCPIP_UDP_SOCKET_DEFAULT_TX_SIZE 512 

Default socket TX buffer size. Note that this setting affects all UDP sockets that are created and, together with TCPIP_UDP_MAX_SOCKETS, has a great impact on the heap size that's used by the stack (see TCPIP_STACK_DRAM_SIZE setting). When large TX bufferrs are needed, probably a dynamic, per socket approach, is a better choice (see TCPIP_UDP_OptionsSet function).