1. Congestion Control

2. Algorithms for Congestion Control
C.c. open loop
acting on SOURCE
acting on DESTINATION
c.c. closed loop
explicit feedback
implicit feedback

3. 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
establishing the TIME OUT

4. 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;

5. 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)