# uip/uip-split.h

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    00001 /*
    00002  * Copyright (c) 2004, Swedish Institute of Computer Science.
    00003  * All rights reserved.
    00004  *
    00005  * Redistribution and use in source and binary forms, with or without
    00006  * modification, are permitted provided that the following conditions
    00007  * are met:
    00008  * 1. Redistributions of source code must retain the above copyright
    00009  *    notice, this list of conditions and the following disclaimer.
    00010  * 2. Redistributions in binary form must reproduce the above copyright
    00011  *    notice, this list of conditions and the following disclaimer in the
    00012  *    documentation and/or other materials provided with the distribution.
    00013  * 3. Neither the name of the Institute nor the names of its contributors
    00014  *    may be used to endorse or promote products derived from this software
    00015  *    without specific prior written permission.
    00016  *
    00017  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
    00018  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    00019  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    00020  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
    00021  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    00022  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
    00023  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    00024  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    00025  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
    00026  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    00027  * SUCH DAMAGE.
    00028  *
    00029  * This file is part of the uIP TCP/IP stack
    00030  *
    00031  * Author: Adam Dunkels <adam@sics.se>
    00032  *
    00033  * $Id: uip-split.h,v 1.2 2006/06/12 08:00:30 adam Exp $
    00034  */
    00035 /**
    00036  * \addtogroup uip
    00037  * @{
    00038  */
    00039
    00040 /**
    00041  * \defgroup uipsplit uIP TCP throughput booster hack
    00042  * @{
    00043  *
    00044  * The basic uIP TCP implementation only allows each TCP connection to
    00045  * have a single TCP segment in flight at any given time. Because of
    00046  * the delayed ACK algorithm employed by most TCP receivers, uIP's
    00047  * limit on the amount of in-flight TCP segments seriously reduces the
    00048  * maximum achievable throughput for sending data from uIP.
    00049  *
    00050  * The uip-split module is a hack which tries to remedy this
    00051  * situation. By splitting maximum sized outgoing TCP segments into
    00052  * two, the delayed ACK algorithm is not invoked at TCP
    00053  * receivers. This improves the throughput when sending data from uIP
    00054  * by orders of magnitude.
    00055  *
    00056  * The uip-split module uses the uip-fw module (uIP IP packet
    00057  * forwarding) for sending packets. Therefore, the uip-fw module must
    00058  * be set up with the appropriate network interfaces for this module
    00059  * to work.
    00060  */
    00061
    00062
    00063 /**
    00064  * \file
    00065  * Module for splitting outbound TCP segments in two to avoid the
    00066  * delayed ACK throughput degradation.
    00067  * \author
    00068  * Adam Dunkels <adam@sics.se>
    00069  *
    00070  */
    00071
    00072 #ifndef __UIP_SPLIT_H__
    00073 #define __UIP_SPLIT_H__
    00074
    00075 /**
    00076  * Handle outgoing packets.
    00077  *
    00078  * This function inspects an outgoing packet in the uip_buf buffer and
    00079  * sends it out using the uip_fw_output() function. If the packet is a
    00080  * full-sized TCP segment it will be split into two segments and
    00081  * transmitted separately. This function should be called instead of
    00082  * the actual device driver output function, or the uip_fw_output()
    00083  * function.
    00084  *
    00085  * The headers of the outgoing packet is assumed to be in the uip_buf
    00086  * buffer and the payload is assumed to be wherever uip_appdata
    00087  * points. The length of the outgoing packet is assumed to be in the
    00088  * uip_len variable.
    00089  *
    00090  */
    00091 void uip_split_output(void);
    00092
    00093 #endif /* __UIP_SPLIT_H__ */
    00094
    00095 /** @} */
    00096 /** @} */