dsredq.h

区分服务的路由算法

/*
 * Copyright (c) 2000 Nortel Networks
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Nortel Networks.
 * 4. The name of the Nortel Networks may not be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY NORTEL AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL NORTEL OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * Developed by: Farhan Shallwani, Jeremy Ethridge
 *               Peter Pieda, and Mandeep Baines
 * Maintainer: Peter Pieda <[e-mail]>
 */

#ifndef dsredq_h
#define dsredq_h

//#include "dsred.h"

#define MAX_PREC 3	// maximum number of virtual RED queues in one physical queue

enum mredModeType {rio_c, rio_d, wred, dropTail};


/*------------------------------------------------------------------------------
struct qParam
    This structure specifies the parameters needed to be maintained for each
RED queue.
------------------------------------------------------------------------------*/
struct qParam {
	edp edp_;		// early drop parameters (see red.h)
	edv edv_;		// early drop variables (see red.h)
	int qlen;		// actual (not weighted) queue length in packets
	double idletime_;	// needed to calculate avg queue
	bool idle_;		// needed to calculate avg queue
};

/*------------------------------------------------------------------------------
class redQueue
    This class provides specs for one physical queue.
------------------------------------------------------------------------------*/
class redQueue {
public:
	int numPrec;	// the current number of precedence levels (or virtual queues)
	int qlim;
	mredModeType mredMode;
	redQueue();
	void config(int prec, const char*const* argv);	// configures one virtual RED queue
	void initREDStateVar(void);		// initializes RED state variables
	void updateREDStateVar(int prec);	// updates RED variables after dequing a packet
        // enques packets into a physical queue
	int enque(Packet *pkt, int prec, int ecn);
	Packet* deque(void);			// deques packets
	double getWeightedLength();
	int getRealLength(void);		// queries length of a physical queue
        // sets packet time constant values
        //(needed for calc. avgQSize) for each virtual queue
	void setPTC(double outLinkBW);
        // sets mean packet size (needed to calculate avg. queue size)
	void setMPS(int mps);


private:
	PacketQueue *q_;		// underlying FIFO queue
        // used to maintain parameters for each of the virtual queues
	qParam qParam_[MAX_PREC];
	void calcAvg(int prec, int m); // to calculate avg. queue size of a virtual queue

};
#endif