Geographic Routing in NS2

Karim Seada

seada@usc.edu

Code Available

• GPSR– Geographic Routing– http://www.icir.org/bkarp/gpsr/gpsr.html

• GRID– Geographic Location Service– http://pdos.lcs.mit.edu/grid/

Greedy Forwarding

Source: GPSR

Perimeter Forwarding

Source: GPSR

GPSR Node Strusture

GPSR Code

• ns-2.1b6 • gpsr/{gpsr.cc,h}: GPSR routing agent• gpsr/paper-cmu.tcl: TCL script (parameter

setting)• tcl/mobility/gpsr.tcl: TCL library• locdbase.{cc,h}: Location database• modify ip.h, packet.h, cmu-trace.cc, and

Makefile.in

GPSR Code

• packet.h: PT_GPSR

• cmu-trace.cc:case PT_GPSR:

format_msg(p, offset);

• ip.h: double dx_, dy_, dz_; //destination position

although there is a separate header!

locdbase.{cc,h}

class LocDbase : public NsObject {public: LocDbase(); ~LocDbase(); MobileNode *nlookup(int);protected: void recv(Packet *, Handler *) { }; int command(int argc, const char * const * argv);private: // lookup table MobileNode **table_; int nn_;};

LocDbase Commands

• int command(int argc, const char * const * argv)– nnodes ‘number of nodes’– register ‘address(id)’ ‘node object’

gpsr.h

• class GPSR_Agent : public Tap, public Agent• class hdr_gpsr• class NeighbEnt• class NeighbTable• class GPSR_BeaconTimer• class GPSR_LastPeriTimer• class GPSR_PlanarTimer

class hdr_gpsr

• static int offset_• int mode_• int currhop_• PeriEnt hops_[MAX_PERI_HOPS_STATIC]• struct PeriEnt peript_• nsaddr_t periptip_[3]• int nhops_

Packet Types

• #define GPSRH_DATA_GREEDY 0 // greedy mode data packet

• #define GPSRH_DATA_PERI 1 // perimeter mode data packet

• #define GPSRH_PPROBE 2 // perimeter probe packet

• #define GPSRH_BEACON 3 // liveness beacon packet

gpsr.cc

• int GPSR_Agent::command(int argc,

const char *const *argv)– node ‘node object’– ldb ‘ldb object’– install-tap ‘mac object’– add-ifq ‘ifq object’– start-gpsr

gpsr.cc

void GPSR_Agent::recv(Packet *p, Handler *){

if ((src == mn_->address()) && (cmh->num_forwards() == 0)) {// packet I am originating? Add header fields & forward

if ((src == mn_->address()) && (gpsrh->mode_ == GPSRH_DATA_GREEDY)) { // packet I sent before? Drop

if (iph->dport_ == GPSR_PORT) { // GPSR Beaconelse forwardPacket(p);

}

Packet Receiving

Packet I am originating?

Data Packet?Packet I sent

Before?GPSR Beacon?

Add header fields & forward

Drop Process Forward

gpsr.cc

void GPSR_Agent::forwardPacket(Packet *p, int rtxflag = 0)

{switch(gpsrh->mode_) case GPSRH_DATA_GREEDY: case GPSRH_DATA_PERI: …cmh->direction_ = -1; // send packet down the stacktarget_->recv(p, (Handler *)0);}

tcl/mobility/gpsr.tcl

• GPSR TCL library functions

• proc create-gpsr-routing-agent { node id }

• proc gpsr-create-mobile-node { id args }

TCL Scripts

• Setting parameters

• Create topography and god

• Create mobile nodes and configure

• Create GPSR agents and attach to nodes

• Mobility scenarios

• Traffic scenarios

Setting Parameters

• val(ragent) Agent/GPSR

• Agent/GPSR set bint_ 3.0

• Agent/GPSR set bdesync_ 0.5

• Agent/GPSR set bexp_ 15.0

• Agent/GPSR set use_mac_ 1

• Agent/GPSR set use_peri_ 1

• Agent/GPSR set peri_proact_ 0

• Agent/GPSR set use_planar_ 1

• Agent/GPSR set use_implicit_beacon_ 1

Creating GPSR Agents

set ldb_ [new LocDbase]

$ldb_ nnodes $val(nn)

for {set i 0} {$i < $val(nn) } {incr i} {

create-gpsr-routing-agent $node_($i) $i

# $ragent_($i) created and started

$ragent_($i) install-tap [$node_($i) set mac_(0)]

$ldb_ register [$node_($i) address?] $node_($i)

$ragent_($i) ldb $ldb_

}

Some Tips

• MobileNode::getLoc(double *x, double *y, double *z)– mn->getLoc(&x, &y, &z);

• ARP• Range

– GridKeeper$gkeeper addnode $node_($i)$node_($i) radius $opt(radius)

– Tx power– setdest

ns-2.1b6 to ns-2.1b9

• hdr_ip *iph = (hdr_ip *) p->access (off_ip_);

change to: hdr_ip *iph = hdr_ip::access(p);

• AF_INET -> NS_AF_INET

• addr_, sport_, dport_ -> addr(), sport(), dport()