# Create simulator object
set ns [new Simulator]
 
# Open files to write trace-data for NAM and Xgraph
set nf [open mm.nam w]
$ns namtrace-all $nf
set f0 [open mm.tr w]
$ns trace-all $f0          

# Finish procedure which closes the trace file and opens Xgraph and NAM
proc finish {} {
        global ns nf f0
        $ns flush-trace
        close $nf
        close $f0
        exec nam mm.nam &
        exit 0
}                            
proc attach-expoo-traffic { node sink size burst idle rate } {
	global ns
		
	set udp [new Agent/UDP]
	$ns attach-agent $node $udp
		
	set traffic [new Application/Traffic/Exponential]
	$traffic set packetSize_ $size
	$traffic set burst_time_ $burst
	$traffic set idle_time_ $idle
	$traffic set rate_ $rate
	$traffic attach-agent $udp

	$ns connect $udp $sink
	return $traffic
}

Agent/LDP set trace_ldp_ 1
Classifier/Addr/MPLS set trace_mpls_ 1

$ns use-scheduler List

$ns rtproto DV

set node0   [$ns node]
$ns node-config -MPLS ON
set LSR1   [$ns node]
set LSR2   [$ns node]
set LSR3   [$ns node]
set LSR4   [$ns node]
set LSR5   [$ns node]
$ns node-config -MPLS OFF
set node6  [$ns node]
 
#
# Define links, bandwidth 1 Mb, delay 10ms, queue managementDropTail
#
$ns duplex-link $node0 $LSR1  1Mb  10ms DropTail
$ns duplex-link $LSR1  $LSR2  1Mb  10ms DropTail  
$ns duplex-link $LSR2  $LSR3  1Mb  10ms DropTail
$ns duplex-link $LSR3  $LSR4  1Mb  10ms DropTail
$ns duplex-link $LSR1  $LSR5  1Mb  10ms DropTail
$ns duplex-link $LSR5  $LSR4  1Mb  10ms DropTail
$ns duplex-link $LSR4  $node6  1Mb  10ms DropTail

#
# configure ldp agents on all mpls nodes
#
for {set i 1} {$i < 6} {incr i} {
	set a LSR$i
	for {set j [expr $i+1]} {$j < 6} {incr j} {
		set b LSR$j
		eval $ns LDP-peer $$a $$b
	}
	set m [eval $$a get-module "MPLS"]
	$m enable-reroute "new"
}

#
# set ldp-message clolr
#
$ns ldp-request-color       blue
$ns ldp-mapping-color       red
$ns ldp-withdraw-color      magenta
$ns ldp-release-color       orange
$ns ldp-notification-color  yellow

Classifier/Addr/MPLS enable-on-demand
Classifier/Addr/MPLS enable-ordered-control
[$LSR1 get-module "MPLS"] enable-data-driven
[$LSR2 get-module "MPLS"] enable-data-driven

# Create a traffic sink and attach it to the node node8
set sink0 [new Agent/LossMonitor]
$ns attach-agent $node6  $sink0
# Create a traffic source
set src0 [ attach-expoo-traffic $node0 $sink0 200 0 0 400k]

$ns at 0.0  "$src0 start"

#for working path
$ns at 0.0  "[$LSR1 get-module MPLS] make-explicit-route 4 1_2_3_4 2000 -1" 

# for reroute
$ns at 0.0  "[$LSR1 get-module MPLS] make-explicit-route 4 5_4 3000 -1"
$ns at 0.1  "[$LSR4 get-module MPLS] make-explicit-route 4 3_2_1_3000  3005  -1"

$ns at 0.2  "[$LSR1 get-module MPLS] flow-erlsp-install   6 -1   2000" 

#routing binding
$ns at 0.3  "[$LSR1 get-module MPLS] reroute-binding      6 -1    3005"
$ns at 0.3  "[$LSR2 get-module MPLS] reroute-binding      6 -1    3005"
$ns at 0.3  "[$LSR3 get-module MPLS] reroute-binding      6 -1    3005"

$ns rtmodel-at 0.5 down $LSR2 $LSR3
$ns rtmodel-at 0.7 up   $LSR2 $LSR3
$ns at 0.8 "$src0 stop"

#
# Displays the erb/lib/pft-table of the given LSR at the command prompt
#
$ns at 0.9 "[$LSR1 get-module MPLS] erb-dump"
$ns at 0.9 "[$LSR1 get-module MPLS] lib-dump"
$ns at 0.9 "[$LSR1 get-module MPLS] pft-dump"
 
# Calls the procedure "finish"
$ns at 1.0 "finish"
 
# The last line finally starts the simulation
$ns run