The question is:
Are the lines I have commented to solve the problem important or can't
affect simulations in any other way?
ns-ib.tcl:
#
# Also reset every queue
#
#foreach qn [array names link_] {
#set q [$link_($qn) queue]
#$q reset
#}
If so, there is an alternative way to solve the problem?
Regards,
2012/3/20 Teerawat@UBC teera...@ece.ubc.ca
HI Richard,
So, what is the question?
Best Wishes,
Teerawat Issariyakul
http://www.ns2ultimate.com/
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http://www.ece.ubc.ca/~teerawat
On Mar 19, 2012, at 11:43 PM, Ricard Alegre wrote:
Dear all,
I wanted to implement a Round Robin packet scheduler just following the
process in the book Introduction to Network Simulator ns2 from Ekran
Hossain:
According to the process I have created the following *.cc and *.h files:
*//classifier-flow.h*
#ifndef ns_gw_flow_classifier_h
#define ns_gw_flow_classifier_h
#include packet.h
#include ip.h
#include classifier.h
class FlowClassifier : public Classifier {
protected:
int classify(Packet *p);
};
#endif
*//classifier-flow.cc*
#include gw_flow_classifier.h
#include stdlib.h
static class FlowClassifierClass : public TclClass {
public:
FlowClassifierClass() : TclClass(Classifier/Flow) {}
TclObject* create(int, const char*const*) {
return (new FlowClassifier());
}
} class_flow_classifier;
int FlowClassifier::classify(Packet *p) {
return hdr_ip::access(p)-flowid();
}
*//pkt-sched.h*
#ifndef ns_gw_pkt_sch_h
#define ns_gw_pkt_sch_h
#include packet.h
#include ip.h
#include connector.h
#include queue.h
#define NS 10
class PktScheduler : public Connector {
public:
PktScheduler();
virtual void handle(Event*);
virtual void recv(Packet*, Handler*);
protected:
void send(int fid, Handler* h);
virtual void resume();
int getFlowID(Packet* p) {return hdr_ip::access(p)-flowid();};
virtual int nextID() = 0;
Handler* qh_[NS];
Packet* pkt_[NS];
int blocked_;
int active_flow_id_;
};
//RR
class RRScheduler : public PktScheduler {
public:
RRScheduler();
private:
virtual int nextID();
int current_id_;
};
#endif
*//pkt-sched.cc*
#include gw_pkt_sch.h
PktScheduler::PktScheduler()
{
int i;
for (i=0;iNS ;i++) {
pkt_[i] = 0;
qh_[i]=0;
}
blocked_ = 0;active_flow_id_ = -1;
}
void PktScheduler::recv(Packet* p, Handler* h)
{
int fid = getFlowID(p);
pkt_[fid] = p;qh_[fid] = h;
if (!blocked_) {
send(fid,this);
blocked_ = 1;
active_flow_id_ = fid;
}
}
void PktScheduler::send(int fid_idx, Handler* h)
{
Connector::send(pkt_[fid_idx],h);
pkt_[fid_idx] = 0;
}
void PktScheduler::handle(Event*) { resume(); }
void PktScheduler::resume()
{
qh_[active_flow_id_]-handle(0);
int index = nextID();
blocked_ = 0;
if (index = 0) {
send(index,this);
blocked_ = 1;
active_flow_id_ = index;
}
}
//RR
RRScheduler::RRScheduler()
{
current_id_ = -1;
}
static class RRSchedulerClass: public TclClass {
public:
RRSchedulerClass() : TclClass(PktScheduler/RR) {}
TclObject* create(int, const char*const*) {
return (new RRScheduler());
}
} class_rr_scheduler;
int RRScheduler::nextID()
{
int count = 0;
current_id_++;current_id_ %= NS;
while((pkt_[current_id_] == 0)(count NS)){
current_id_++;current_id_ %= NS;
count++;
}
if (count == NS)
return -1;
else{
return current_id_;
}
}
*And the following Otcl file:*
*#ns-link.tcl*
Class LinkSch -superclass Link
LinkSch instproc init {src dst bw delay num_queues} {
$self next $src $dst
$self instvar link_ queue_ head_ toNode_ ttl_
$self instvar drophead_
$self instvar num_queues_ sch_ flow_clsfr_
set ns [Simulator instance]
set head_ [new Connector]
set drophead_ [new Connector]
set link_ [new DelayLink]
set ttl_ [new TTLChecker]
set flow_clsfr_ [new Classifier/Flow]
set sch_ [new PktScheduler/RR]
set num_queues_ $num_queues
$head_ set link_ $self
$drophead_ target [$ns set nullAgent_]
$head_ target $flow_clsfr_
for {set i 0} {$i $num_queues_} {incr i} {
set queue_($i) [new Queue/DropTail]
$queue_($i) target $sch_
$queue_($i) drop-target $drophead_
}
$sch_ target $link_
$link_ target $ttl_
$link_ drop-target $drophead_
$link_ set bandwidth_ $bw
$link_ set delay_ $delay
$ttl_ target [$dst entry]
$ttl_ drop-target $drophead_
}
LinkSch instproc add-flow { fid } {
$self instvar queue_ flow_clsfr_
