ftp-scenario.tcl

对IEEE 802.11e里的分布式信道接入算法EDCA进行改进

#
# A wireless lan scenario with ftp traffic over tcp
# 
#

# defaults
set num_nodes 3
set packet_size 256

proc create_scenario { } {
	global ns_ node_
	global num_nodes packet_size

	# num_nodes should be odd
	if {[expr $num_nodes % 2] == 0} {
		puts "num_nodes should be odd"
		exit
	}

	set num_ftp [expr ($num_nodes - 1) / 2]

	for {set i 0} {$i < $num_ftp} {incr i} {
		set n [expr (2 * $i) + 1]
		set client $node_($n)
		set server $node_([expr $n + 1])

		set src [new Agent/TCP]
		$src set class_ [expr 2 + $i]
		$src set syn_ 1
		$src set packetSize_ $packet_size
		$ns_ attach-agent $client $src

		set sink [new Agent/TCPSink/DelAck]
		$ns_ attach-agent $server $sink

		$ns_ connect $src $sink

		set ftp [new Application/FTP]
		$ftp attach-agent $src

		$ns_ at [expr 3.0 + ($i * 0.1)] "$ftp start"
	}
}