"0x7d" - 1 õppematerjal

Tööstuslik andmeside kontrolltöö 2 abimaterjal - vastused

synchronization ­ Frame Synchronization ~ Asynchronous Transmission using STX & ETX 1. obtain recoveryoDLC service modes:> Connection­oriented vs connectionless Example of PPP byte stuffing: bit synchronization with 1st SYN ­ starts receiving bits 2. enter hunt mode for byte synchronization: 1. Reliable/virtual-circuit (connection-oriented mode) ­­ users establish Flag=0x7E (01111110), Control escape=0x7D (01111101) after each bit -> check last 8 bits 3. frame synchronization: process each byte looking for STX - after connection before sending information packets­ errors dealt with using ACKs, Any occurrence of flag or control escape inside of frame is STX, read frame contents look for ETX ­ after ETX, transmitter can maintain synch by sending SYNs, NACKS2