Source: wikibot/application-layer-protocol-negotiation
= Application-Layer Protocol Negotiation
{wiki=Application-Layer_Protocol_Negotiation}
Application-Layer Protocol Negotiation (ALPN) is an extension to the Transport Layer Security (TLS) protocol that allows clients and servers to negotiate which application-layer protocol they will use over a secure connection. It is especially useful in scenarios where a single port is used for multiple protocols, such as HTTP/1.1, HTTP/2, or even other protocols like WebSocket.