network simulator 2
TRANSCRIPT
What is ns?
Object-oriented, discrete event driven network simulator
It was normally used in wired & wireless protocol Written in C++ and OTcl
ADVANTAGES
1. Debugging of errors makes easy,2. It is cheap doesnot not require any equipment,3. Even an complex scenario can be tested effiently.
ns Architecture
Tcl
OTcl
TclCL
ns-2
Even
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ched
ule
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Network Components
C/C++
Simulation NetworkWired Network
Routing: Distance Vector, Link StateTransportation: TCP and UDPQueuing disciplines: drop-tail
WirelessAd-hoc routing and mobile IP: AODVSensor-MAC, WiMAX (new)Power control in wireless networks
NS2 Functionalities
Traffic models and applications◦ FTP, CBR
Transport protocols◦ Unicast: TCP, UDP
Routing and queuing◦ Wired and ad-hoc routing◦ Queuing protocols: drop-tail, etc
Physical media◦ Wired (point-to-point, LANs), wireless (multiple
propagation models), satellite
Ns – structure
Types
1. Event Schedular2. Turn on Tracing3. Network Topology4.Transport Connection5. Generate Traffic6.Start Simulation
Attaching Transport Agents to Nodes-tcp/udp
TCP :set src [new Agent/TCP/FullTcp]set sink [new Agent/TCP/FullTcp]$ns_ attach-agent $node_(s1) $src$ns_ attach-agent $node_(k1) $sink$ns_ connect $src $sink
Udp agentSet udp0 [new Agent/Null]ns attach-agent $n0 $udp0set cbr0 [new Application/Traffic/CBR]$cbr0 attach-agent $udp0$udp0 set packetSize_ 536 ; #(max=1000)set null0 [new Agent/Null]$ns attach-agent $n1 $null0$ns connect $udp0 $null0
PACKETS
It is the collection of data,whether header is called or not all header files where present in the stack registers.
Cmn header
Ip header
Tcp header
Rtp header
Trace header
Header
data
Trace AnalysisTrace packets on individual linkTracefile format:
NAM ns has a companion network animator called nam
hence, has been called the nsnam project
Xgraph One part of the ns-allinone package is 'xgraph', a
plotting program which can be used to create graphic representations of simulation results.