1 Multicast in ns-2 報告者 : 陳沐恩

2 Multicast 簡介

3 Multicast Routing set ns [new Simulator] $ns multicast Or set ns [new Simulator – multicast on] set mproto :CtrMcast, DM, ST, BST

4 Multicast Routing all nodes will contain multicast protocol agents  set mrthandle [$ns mrtproto $mproto] allocating a multicast address  set group [Node allocaddr] define an agent and as a multicast source for the group  $udp1 set dst_addr_ $group  $udp1 set dst_port_ 0

5 Multicast Routing create a receiver agent  set rcvr [new Agent/LossMonitor] specify which nodes join the group and when they want to join the group  $ns at 0.0 "$n1 join-group $rcvr $group" make a node leave the group at a time  $ns at 1.6 "$n2 leave-group $rcvr $group"

6 Multicast:Step1 Scheduler, tracing, and topology # Create scheduler set ns [new Simulator] # Turn on multicast $ns multicast # Turn on Tracing set fd [new “mcast.nam” w] $ns namtrace-all $fd

7 Multicast:Step2 Topology # Create nodes set n0 [$ns node] set n1 [$ns node] set n2 [$ns node] set n3 [$ns node] # Create links $ns duplex-link $n0 $n1 1.5Mb 10ms DropTail $ns duplex-link $n0 $n2 1.5Mb 10ms DropTail $ns duplex-link $n0 $n3 1.5Mb 10ms DropTail

8 Multicast:Step3 Routing and group setup # Routing protocol: let’s run distance vector set mproto DM # Allocate group addresses set group1 [Node allocaddr] set group2 [Node allocaddr]

9 Multicast:Step4 Sender0 # Transport agent for the traffic source set udp0 [new Agent/UDP] $ns attach-agent $n1 $udp0 $udp0 set dst_addr_ $group1 $udp0 set dst_port_ 0 # Constant Bit Rate source #0 set cbr0 [new Application/Traffic/CBR] $cbr0 attach-agent $udp0 # Start at time 1.0 second $ns at 1.0 "$cbr0 start"

10 Multicast:Step5 Sender1 # Transport agent for the traffic source set udp1 [new Agent/UDP] $ns attach-agent $n3 $udp1 $udp1 set dst_addr_ $group2 $udp1 set dst_port_ 0 # Constant Bit Rate source #0 set cbr1 [new Application/Traffic/CBR] $cbr1 attach-agent $udp1 # Start at time 1.1 second $ns at 1.1 "$cbr1 start"

11 Multicast:Step6 Receiver with dynamic membership # Can also be Agent/Null set rcvr [new Agent/LossMonitor] # Assign it to node $n2 $ns at 1.2 "$n2 join-group $rcvr $group2" $ns at 1.25 "$n2 leave-group $rcvr $group2" $ns at 1.3 "$n2 join-group $rcvr $group2" $ns at 1.35 "$n2 join-group $rcvr $group1"

12 Multicast:Step7 End-of-simulation wrapper (as usual) $ns at 2.0 "finish" proc finish {} { global ns fd close $fd $ns flush-trace puts "running nam..." exec nam out.nam & exit 0 } $ns run

13 抽考題目 使用 DM 這個 multicast protocol ，讓所有 node 包含 multicast protocol agent ，並建立一個 multicast 的 group ，定義一個 udp 的 agent 給 group 當作 multicast 的來源端。 提供 tcl ，請依要求補上缺少的 code(5 行 )