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Pequena apresentação de 15 minutos sobre WebSockets na disciplina de "programação para redes de computadores"
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WEBSOCKETSRodr igo Constant in Ctenas Zaccara
6367629
Wednesday, November 23, 2011
STANDARDIZATION
• Internet Engineering Task Force
• Protocol
• World Wide Web Consortium
• JavaScript API
Wednesday, November 23, 2011
PROTOCOL
Wednesday, November 23, 2011
HANDSHAKE
• HTTP
• Connection: upgrade
• Upgrade: websocket
• Sec-WebSocket-* headers
Wednesday, November 23, 2011
MESSAGE EXCHANGE
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1+-+-+-+-+-------+-+-------------+-------------------------------+|F|R|R|R| opcode|M| Payload len | Extended payload length ||I|S|S|S| (4) |A| (7) | (16/63) |
|N|V|V|V| |S| | (if payload len==126/127) || |1|2|3| |K| | |+-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - +| Extended payload length continued, if payload len == 127 |+ - - - - - - - - - - - - - - - +-------------------------------+
| |Masking-key, if MASK set to 1 |+-------------------------------+-------------------------------+| Masking-key (continued) | Payload Data |+-------------------------------- - - - - - - - - - - - - - - - +: Payload Data continued ... :
+ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +| Payload Data continued ... |+---------------------------------------------------------------+
Wednesday, November 23, 2011
JAVASCRIPT API
Wednesday, November 23, 2011
METHODS
• send
• Callback style
• onopen
• onclose
• onerror
• onmessage
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COMPARISON
Wednesday, November 23, 2011
HTTP POOLING
• protocol overhead: 600 bytes
users Traffic (bytes) Traffic (Mbps)
1000 600000 4.5
10000 6000000 45
100000 60000000 450
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WEBSOCKET
• protocol overhead: 2 bytes
users Traffic (bytes) Traffic (Mbps)
1000 2000 0.019
10000 20000 0.19
100000 200000 1.9
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DEMO
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CONCLUSION
• WebSocket is the choice for web real time communication
• Very efficient network traffic
• Full duplex (connection always ready for client and server)
Wednesday, November 23, 2011
WEBSOCKETSRodr igo Constant in Ctenas Zaccara
6367629
Wednesday, November 23, 2011
