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Congestion Control. Algorithms for Congestion Control. C.c. open loop acting on SOURCE acting on DESTINATION c.c. closed loop explicit feedback implicit feedback. Influence on Congestion. Data Link level retransmission policy out-of-order packet caching confirmation policy
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Algorithms for Congestion Control • C.c. open loop • acting on SOURCE • acting on DESTINATION • c.c. closed loop • explicit feedback • implicit feedback
Influence on Congestion • Data Link level • retransmission policy • out-of-order packet caching • confirmation policy • flux control policy • Network level • virtual circuit or datagrams • management of packets in routers • packet elimination policy • routing algorithms • management of “time-to-live” • Transport level • retransmission policy • out-of-order packet caching • confirmation policy • flux control policy • establishing the TIME OUT
QOS for transport layer • Connection establishment delay; • connection establishment failure probability; • transit delay; • residence error rate; • transfer error probability; • connection release delay; • connection release failure probability; • protection; • resilience; • option negociation;
The token bucket algorithm • C+*S = M*S • S = C/(M - ) • S - the output burst length (sec); • C - the bucket capacity (nr. bytes); • - the arriving token rate ( bytes/sec); • M - the maximum output rate (bytes/sec)