Pequena apresentação de 15 minutos sobre WebSockets na disciplina de "programação para redes de computadores"

1. WEBSOCKETS
Rodr igo Constantin Ctenas Zaccar a
6367629
Wednesday, November 23, 2011

2. STANDARDIZATION
• Internet Engineering Task Force
• Protocol
• World Wide Web Consortium
• JavaScript API
Wednesday, November 23, 2011

3. PROTOCOL
Wednesday, November 23, 2011

4. HANDSHAKE
• HTTP
• Connection: upgrade
• Upgrade: websocket
• Sec-WebSocket-* headers
Wednesday, November 23, 2011

5. 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

6. JAVASCRIPT API
Wednesday, November 23, 2011

7. METHODS
• send
• Callback style
• onopen
• onclose
• onerror
• onmessage
Wednesday, November 23, 2011

8. COMPARISON
Wednesday, November 23, 2011

9. HTTP POOLING
• protocol overhead: 600 bytes
users Traffic (bytes) Traffic (Mbps)
1000 600000 4.5
10000 6000000 45
100000 60000000 450
Wednesday, November 23, 2011

10. WEBSOCKET
• protocol overhead: 2 bytes
users Traffic (bytes) Traffic (Mbps)
1000 2000 0.019
10000 20000 0.19
100000 200000 1.9
Wednesday, November 23, 2011

11. DEMO
Wednesday, November 23, 2011

12. 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

13. WEBSOCKETS
Rodr igo Constantin Ctenas Zaccar a
6367629
Wednesday, November 23, 2011