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/* -*- Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
/*
* Copyright (c) 1996-1997 The Regents of the University of California.
* 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 the Daedalus
* Research Group at the University of California, Berkeley.
* 4. Neither the name of the University nor of the Research Group may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 THE REGENTS 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.
*
* ack-recons.cc: contributed by the Daedalus Research Group,
* UC Berkeley (http://daedalus.cs.berkeley.edu).
*
* $Header: /cvsroot/nsnam/ns-2/tcp/ack-recons.h,v 1.4 2000/09/01 03:04:05 haoboy Exp $
*/
/*
* TCP Ack reconstructor. This object sits on the other end of a constrained
* link and intersperses TCP acks to the source (without violating the e2e
* semantics of TCP acks). This allows us to get good performance for TCP
* over various asymmetric networks, in conjunction with techniques to reduce
* the frequency of acks (such as ack filtering) with making any changes to
* the TCP source (e.g., like those implemented in tcp-asym.cc).
*/
#ifndef ns_ack_recons_h
#define ns_ack_recons_h
#include "semantic-packetqueue.h"
class AckReconsController : public TclObject {
public:
AckReconsController() : spq_(0) {}
void recv(Packet *p, Handler *h=0);
SemanticPacketQueue *spq_;
};
class AckRecons : public Agent {
public:
AckRecons(nsaddr_t src, nsaddr_t dst) :
Agent(PT_TCP), spq_(0), src_(src), dst_(dst),
ackTemplate_(0), ackPending_(0), lastAck_(0),
lastRealAck_(0) {
bind("lastTime_", &lastTime_);
bind("lastAck_", &lastAck_);
bind("lastRealTime_", &lastRealTime_);
bind("lastRealAck_", &lastRealAck_);
bind("ackInterArr_", &ackInterArr_);
bind("ackSpacing_", &ackSpacing_);
bind("deltaAckThresh_", &deltaAckThresh_);
bind("delack_", &delack_);
bind("adaptive_", &adaptive_);
bind("alpha_", &alpha_);
bind("size_", &size_);
}
int command(int argc, const char*const* argv);
void handle(Event *e);
void recv(Packet *p);
SemanticPacketQueue *spq_; /* the corresponding queue of packets */
private:
void sendack(int ack, double t); /* send ack pkt at time t */
nsaddr_t src_; /* src addr:port */
nsaddr_t dst_; /* dst addr:port */
Packet *ackTemplate_; /* used as a template for generated acks */
int ackPending_;
int lastAck_; /* last ack sent by recons, maybe generated */
int lastRealAck_; /* last ack actually received on link */
double lastTime_; /* time when last ack was sent */
double lastRealTime_; /* time when last ack arrived on link */
int dupacks_; /* number of dup acks seen so far */
int size_; /* TCP packet size -- needed because TCP
* acks are in terms of packets */
/* knobs/policies */
int deltaAckThresh_; /* threshold for reconstruction to kick in */
double ackInterArr_; /* estimate of arrival rate of acks */
double ackSpacing_; /* time duration between acks sent by recons */
int delack_; /* generate ack at least every delack_ acks */
int adaptive_; /* whether to adapt ack bandwidth? */
double alpha_; /* used in linear filter for ack rate est. */
};
#endif
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