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en:netzer:websockets [2013/02/22 22:25] svesch [A simple example] |
en:netzer:websockets [2014/02/09 14:32] (current) |
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| - | ====== Why WebSockets? ====== | + | ====== WebSocket ====== |
| + | |||
| + | WebSocket is a protocol for bidirectional communication between a web application and a server via a TCP connection.\\ | ||
| + | Netzer uses WebSocket as a channel for the [[commandinterface|command interface]]. | ||
| + | |||
| + | |||
| + | ====== Why WebSocket? ====== | ||
| In normal HTTP a client (i.e. the browser) sends a request to a server. After some processing time the server responses to the client. This is one way, the server can not serve files or data by itself without been requested before. | In normal HTTP a client (i.e. the browser) sends a request to a server. After some processing time the server responses to the client. This is one way, the server can not serve files or data by itself without been requested before. | ||
| This is a disadvantage i.e. if data must be asynchronously refreshed. In such cases the client has to poll the server which leads to a lot of traffic. | This is a disadvantage i.e. if data must be asynchronously refreshed. In such cases the client has to poll the server which leads to a lot of traffic. | ||
| - | WebSockets are a possibilty for bidirectional communication between server and client. Client and server can send data on demand - Both are equal communication partners. While refreshing data it is enough to send data as soon they are available. It is not necessary anymore to poll the server. | + | WebSocket are a possibilty for bidirectional communication between server and client. Client and server can send data on demand - Both are equal communication partners. While refreshing data it is enough to send data as soon they are available. It is not necessary anymore to poll the server. |
| <note important> | <note important> | ||
| - | Netzer supports Websockets since Version 1.5! | + | Netzer supports Websocket since Version 1.5! |
| </note> | </note> | ||
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| + | |||
| + | ====== Limitations ====== | ||
| + | |||
| + | Because an active WebSocket connection needs an active TCP connection to the web server of Netzer the further access of web pages is blocked. | ||
| + | Also only one simultaneous WebSocket connection is possible. | ||
| + | |||
| + | |||
| + | ===== Supported commands ===== | ||
| + | |||
| + | All commands of the [[commandinterface|command interface]] are supported. | ||
| + | There are no WebSocket specific commands. | ||
| ====== WebSocket URI ====== | ====== WebSocket URI ====== | ||
