Primary send command to secondary, secondary send response to Primary (It can send data, If Primary ask)
ABM - Asynchronous Balance mode
No Primary and Secondary (Problem : support just point to point)
HLCD
I-frame - first bit in control field is 0
(Pole and Final
If it send 1 and send from primary to secondary - call pole
If it send 1 and come from secondary - call final
but If it send 0 that mean don't want to use this bit)
S-frame - first 2 bit in control field is 1 0
(RR - receive ready, same as ASK
RNR - receiver not ready to receive next frame, just stop sending data
REJ(go-back-N ARQ) - reject
SREJ - selective reject)
U-frame - first 2 bit in control field is 1 1
Point to point Protocol (PPP)
use when access internet to house, use only U-frame
Byte stuffing - If want to send flag as a data have to use ESC to make that be data
Link Establishing - LCP
Authenticating - PAP, CHAP
Network layer establishment - IPCP
Network termination - IPCP
Link terminating - LCP
Factor affecting network efficiency
- circuit
- error control techniques
- protocol used
Efficiency of protocol in % = total number of info bits to be transmitted/total number of bits transmitted
(Bigger the message length, better the efficiency - If use very large frame, It will have more chance to get error/Maximum 1500)
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