uIP 1.0: uip/uip-split.h Source File

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 /** @} */
+