The total number of sockets supported is limited by the available RAM. A compile-time check is done to make sure that enough sockets are available for selected TCP/UDP applications. This can be configured using the MPLAB® Harmony Configurator (MHC).
To configure the maximum number of sockets allowed, expand the following MHC selection tree:
Harmony Framework Configuration > TCPIP Stack > Use TCP\IP Stack?
Check and expand the 'Use TCP' and/or 'Use UDP' selections to find the Max Sockets text box.
Note that sockets are physically implemented as buffers in SRAM. The more sockets you use, the more RAM will be consumed. You are responsible to determine the maximum number of sockets the project can handle. When defining these limits, take into account the number of interfaces the project stack is supporting.
For more details on the TCP/IP stack, see the Harmony Help File.