WITHOUT FLOW CONTROL LIDS when overload occurs queues build up packets are discarded Sources retransmit messages congestion increases = instability Flow control prevents network instability by keeping packets waiting outside the network rather than in queues inside the network Avoids wasting network resources Prevent"disasters” Laboratory for Information and Decision SystemsWITHOUT FLOW CONTROL QuickTime™ and a GIF decompressor are needed to see this picture. QuickTime™ and a Photo - JPEG decompressor are needed to see this picture. LIDS • When overload occurs – queues build up – packets are discarded – Sources retransmit messages – congestion increases => instability • Flow control prevents network instability by keeping packets waiting outside the network rather than in queues inside the network – Avoids wasting network resources – Prevent “disasters” Eytan Modiano Slide 3 Lab oratory for Information and Decision Systems