1 /* 2 * Copyright (c) 2004, Swedish Institute of Computer Science. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the Institute nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * This file is part of the uIP TCP/IP stack 30 * 31 * Author: Adam Dunkels <[email protected]> 32 * 33 * $Id: uip-split.h,v 1.2 2006/06/12 08:00:30 adam Exp $ 34 */ 35 /** 36 * \addtogroup uip 37 * @{ 38 */ 39 40 /** 41 * \defgroup uipsplit uIP TCP throughput booster hack 42 * @{ 43 * 44 * The basic uIP TCP implementation only allows each TCP connection to 45 * have a single TCP segment in flight at any given time. Because of 46 * the delayed ACK algorithm employed by most TCP receivers, uIP's 47 * limit on the amount of in-flight TCP segments seriously reduces the 48 * maximum achievable throughput for sending data from uIP. 49 * 50 * The uip-split module is a hack which tries to remedy this 51 * situation. By splitting maximum sized outgoing TCP segments into 52 * two, the delayed ACK algorithm is not invoked at TCP 53 * receivers. This improves the throughput when sending data from uIP 54 * by orders of magnitude. 55 * 56 * The uip-split module uses the uip-fw module (uIP IP packet 57 * forwarding) for sending packets. Therefore, the uip-fw module must 58 * be set up with the appropriate network interfaces for this module 59 * to work. 60 */ 61 62 63 /** 64 * \file 65 * Module for splitting outbound TCP segments in two to avoid the 66 * delayed ACK throughput degradation. 67 * \author 68 * Adam Dunkels <[email protected]> 69 * 70 */ 71 72 #ifndef __UIP_SPLIT_H__ 73 #define __UIP_SPLIT_H__ 74 75 /** 76 * Handle outgoing packets. 77 * 78 * This function inspects an outgoing packet in the uip_buf buffer and 79 * sends it out using the uip_fw_output() function. If the packet is a 80 * full-sized TCP segment it will be split into two segments and 81 * transmitted separately. This function should be called instead of 82 * the actual device driver output function, or the uip_fw_output() 83 * function. 84 * 85 * The headers of the outgoing packet is assumed to be in the uip_buf 86 * buffer and the payload is assumed to be wherever uip_appdata 87 * points. The length of the outgoing packet is assumed to be in the 88 * uip_len variable. 89 * 90 */ 91 void uip_split_output(void); 92 93 #endif /* __UIP_SPLIT_H__ */ 94 95 /** @} */ 96 /** @} */ 97