101 Switching Protocols response code indicates
the protocol the server is switching to as requested by a client which sent the message
Upgrade request header.
101 Switching Protocols
Switching protocols might be used with WebSockets.
HTTP/1.1 101 Switching Protocols Upgrade: websocket Connection: Upgrade
|RFC 7231, section 6.2.2: 101 Switching Protocol||Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content|