5. VTU COMPUTER NETWORK LAB | READ NOW
VTU COMPUTER NETWORK LAB
Program 5:- Implement and study the performance of GSM on NS2/NS3 (Using MAC layer) or
equivalent environment
Program Code
#set Parameters set stop 100 ;# Stop time. # Topology set type gsm ;#type of link: # AQM parameters set minth 30 set maxth 0 set adaptive 1 ;# 1 for Adaptive RED, 0 for plain RED # Traffic generation. set flows 0 ;# number of long-lived TCP flows set window 30 ;# window for long-lived traffic # Plotting statistics. set opt(wrap) 100 ; # wrap plots? set opt(srcTrace) is ;# where to plot traffic set opt(dstTrace) bs2 ;# where to plot traffic #default downlink bandwidth in bps set bwDL(gsm) 9600 #default downlink propagation delay in seconds set propDL(gsm) .500 set ns [new Simulator] set tf [open Mlab5.tr w] $ns trace-all $tf set nodes(is) [$ns node] set nodes(ms) [$ns node] set nodes(bs1) [$ns node] set nodes(bs2) [$ns node] set nodes(lp) [$ns node] proc cell_topo {} { global ns nodes $ns duplex-link $nodes(lp) $nodes(bs1) 3Mbps 10ms DropTail $ns duplex-link $nodes(bs1) $nodes(ms) 1 1 RED $ns duplex-link $nodes(ms) $nodes(bs2) 1 1 RED $ns duplex-link $nodes(bs2) $nodes(is) 3Mbps 50ms DropTail puts "GSM Cell Topology" } proc set_link_params {t} { global ns nodes bwDL propDL $ns bandwidth $nodes(bs1) $nodes(ms) $bwDL($t) duplex $ns bandwidth $nodes(bs2) $nodes(ms) $bwDL($t) duplex $ns delay $nodes(bs1) $nodes(ms) $propDL($t) duplex $ns delay $nodes(bs2) $nodes(ms) $propDL($t) duplex $ns queue-limit $nodes(bs1) $nodes(ms) 10 $ns queue-limit $nodes(bs2) $nodes(ms) 10 } # RED and TCP parameter Queue/RED set adaptive_ $adaptive Queue/RED set thresh_ $minth Queue/RED set maxthresh_ $maxth Agent/TCP set window_ $window #Create topology switch $type { gsm {cell_topo} } set_link_params $type $ns insert-delayer $nodes(ms) $nodes(bs1) [new Delayer] $ns insert-delayer $nodes(ms) $nodes(bs2) [new Delayer] # Set up forward TCP connection if {$flows == 0} { set tcp1 [$ns create-connection TCP/Sack1 $nodes(is) TCPSink/Sack1 nodes(lp) 0] set ftp1 [[set tcp1] attach-app FTP] $ns at 0.8 "[set ftp1] start" } proc stop {} { global nodes opt tf set wrap $opt(wrap) set sid [$nodes($opt(srcTrace)) id] set did [$nodes($opt(dstTrace)) id] set a "Mlab5.tr" set GETRC "/var/cn/ns-allinone-2.35/ns-2.35/bin/getrc" set RAW2XG "/var/cn/ns-allinone-2.35/ns-2.35/bin/raw2xg" exec $GETRC -s $sid -d $did -f 0 Mlab5.tr | \ $RAW2XG -s 0.01 -m $wrap -r > plot.xgr exec $GETRC -s $did -d $sid -f 0 Mlab5.tr | \ $RAW2XG -a -s 0.01 -m $wrap >> plot.xgr exec xgraph -x time -y packets plot.xgr & exit 0 } $ns at $stop "stop" $ns run