ns and incoming packets, and as a mount point for the listener filter and network filter.</li><li>Protocol is the multi-protocol engine layer that examines packets and uses the corresponding protocol for decode/encode processing.</li><li>Stream does a secondary encapsulation of the decode packet into stream, which acts as a mount for the stream filter.</li><li>Proxy acts as a forwarding framework for MOSN, and does proxy processing on the encapsulated streams.</li></ul><h2 id=why-use-mosn>Why use MOSN?</h2>