ard against the <a class="el" href="tcp_8h.html">tcp.h</a> functions while providing the same functionality. It is used to e.g. add SSL/TLS (see LWIP_ALTCP_TLS) or proxy-connect support to an application written for the tcp callback API without that application knowing the protocol details.</p>
<ul>
<li>This interface mimics the tcp callback API to the application while preventing direct linking (much like virtual functions).</li>
<li>This way, an application can make use of other application layer protocol