Broadcast Routing Route a packet from a source to all nodes in the network Possible solutions: – Flooding: Each node sends packet on all outgoing links Discard packets received a second time – Spanning Tree Routing: Send packet along a tree that includes all of the nodes in the network
Routing Must choose routes for various origin destination pairs (O/D pairs) or for various sessions – Datagram routing: route chosen on a packet by packet basis Using datagram routing is an easy way to split paths – Virtual circuit routing: route chosen a session by session basis
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 Flow control: end-to-end mechanism for regulating traffic between source and destination
Service times M/G/1 General independent Poisson arrivals at rate λ Service time has arbitrary distribution with given E[X] and E[X2] – Service times are independent and identically
Carrier Sense Multiple Access (CSMA) In certain situations nodes can hear each other by listening to the channel “Carrier Sensing” CSMA: Polite version of Aloha
An interesting property of an M/M/1 queue, which greatly simplifies combining these queues into a network, is the surprising fact that the output of an M/M/1 queue with arrival rate λ is a Poisson process of rate