REDQueue Class Reference

#include <REDQueue.h>

Inheritance diagram for REDQueue:

List of all members.

---

Detailed Description

RED queue. See NED for more info.

Protected Member Functions
virtual void	initialize ()
virtual void	finish ()
virtual bool	enqueue (cMessage *msg)
virtual cMessage *	dequeue ()
Protected Attributes
double	wq
double	minth
double	maxth
double	maxp
double	pkrate
cQueue	queue
double	avg
simtime_t	q_time
int	count
cOutVector	avgQlenVec
cOutVector	qlenVec
cOutVector	dropVec
long	numEarlyDrops

---

Member Function Documentation

cMessage * REDQueue::dequeue (   )  [protected, virtual]

Redefined from PassiveQueueBase. Implements PassiveQueueBase. { if (queue.empty()) return NULL; //" // when queue becomes empty // q_time <- time //" cMessage *pk = (cMessage *)queue.pop(); if (queue.length()==0) q_time = simTime(); // statistics qlenVec.record(queue.length()); return pk; }

bool REDQueue::enqueue (  cMessage *  msg  )  [protected, virtual]

Redefined from PassiveQueueBase. Implements PassiveQueueBase. { //" // for each packet arrival // calculate the new average queue size avg: // if the queue is nonempty // avg <- (1-wq)*avg + wq*q // else // m <- f(time-q_time) // avg <- (1-wq)^m * avg //" if (!queue.empty()) { avg = (1-wq)*avg + wq*queue.length(); } else { // Note: f() is supposed to estimate the number of packets // that could have arrived during the idle interval (see Section 11 // of the paper). We use pkrate for this purpose. double m = (simTime()-q_time) * pkrate; avg = pow(1-wq, m) * avg; } // statistics avgQlenVec.record(avg); //" // if minth <= avg < maxth // increment count // calculate probability pa: // pb <- maxp*(avg-minth) / (maxth-minth) // pa <- pb / (1-count*pb) // with probability pa: // mark the arriving packet // count <- 0 // else if maxth <= avg // mark the arriving packet // count <- 0 // else count <- -1 //" bool mark = false; if (minth<=avg && avg<maxth) { count++; double pb = maxp*(avg-minth) / (maxth-minth); double pa = pb / (1-count*pb); if (dblrand() < pa) { EV << "Random early packet drop (avg queue len=" << avg << ", pa=" << pa << ")\n"; mark = true; count = 0; numEarlyDrops++; } } else if (maxth <= avg) { EV << "Avg queue len " << avg << " >= maxth, dropping packet.\n"; mark = true; count = 0; } else { count = -1; } // carry out decision if (mark || queue.length()>=maxth) // maxth is also the "hard" limit { delete msg; dropVec.record(1); return true; } else { queue.insert(msg); qlenVec.record(queue.length()); return false; } }

void REDQueue::finish (   )  [protected, virtual]

Reimplemented from PassiveQueueBase. { PassiveQueueBase::finish(); recordScalar("packets dropped early by RED", numEarlyDrops); }

void REDQueue::initialize (   )  [protected, virtual]

Reimplemented from PassiveQueueBase. { PassiveQueueBase::initialize(); queue.setName("l2queue"); avgQlenVec.setName("avg queue length"); qlenVec.setName("queue length"); dropVec.setName("drops"); // configuration wq = par("wq"); minth = par("minth"); maxth = par("maxth"); maxp = par("maxp"); pkrate = par("pkrate"); // state avg = 0; q_time = 0; count = -1; numEarlyDrops = 0; WATCH(avg); WATCH(q_time); WATCH(count); WATCH(numEarlyDrops); }

---

Member Data Documentation

double REDQueue::avg [protected]

cOutVector REDQueue::avgQlenVec [protected]

int REDQueue::count [protected]

cOutVector REDQueue::dropVec [protected]

double REDQueue::maxp [protected]

double REDQueue::maxth [protected]

double REDQueue::minth [protected]

long REDQueue::numEarlyDrops [protected]

double REDQueue::pkrate [protected]

simtime_t REDQueue::q_time [protected]

cOutVector REDQueue::qlenVec [protected]

cQueue REDQueue::queue [protected]

double REDQueue::wq [protected]

---

The documentation for this class was generated from the following files:

• REDQueue.h
• REDQueue.cc

---