adamdunkels | a2f3c42 | 2004-09-12 20:24:53 +0000 | [diff] [blame] | 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 Contiki operating system. |
| 30 | * |
| 31 | * Author: Adam Dunkels <adam@sics.se> |
| 32 | * |
| 33 | * $Id: uip-split.h,v 1.2 2004/09/12 20:24:56 adamdunkels Exp $ |
| 34 | */ |
adamdunkels | ee26fe3 | 2004-03-25 09:47:10 +0000 | [diff] [blame] | 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 <adam@sics.se> |
| 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 | /** @} */ |