https://devzone.nordicsemi.com/f/nordic-q-a/122533/openthread-feature-set-ftdHello Why doesn&#39;t FTD support TCP-related features? docs.nordicsemi.com/.../prebuilt_libs.htmlen-USTelligent Community 13Fri, 27 Jun 2025 09:01:41 GMThttps://devzone.nordicsemi.com/thread/540679?ContentTypeID=1Fri, 27 Jun 2025 09:01:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9a3be981-714e-40f4-afad-027527b8975etesc<p>Hi,</p> <p>The optimized FTD and MTD variants are primarily tailored for Matter, where TCP is not used. Adding unneeded features would add unnecessarily to memory requirements.</p> <p>For the full set of features you can use the Master variant.</p> <p>Alternatively, it should be possible to add TCP features to the FTD or MTD variant by configuring and building OpenThread from sources (CONFIG_OPENTHREAD_SOURCES). Please note however that custom builds like that are not necessarily covered by our <a href="https://docs.nordicsemi.com/bundle/comp_matrix_nrf52840/page/COMP/nrf52840/nrf52840_thread_cids.html">Thread certifications</a>. Please contact the certification body in the Thread Group, if you need clarification whether or not it would be&nbsp;acceptable to receive Certification by Inheritance for the Optimized MTD/FTD variant built from sources with TCP enabled. For instance, some additional testing may be required.</p> <p>Regards,<br />Terje</p><div style="clear:both;"></div>