osd-contiki/core/net/ip/uip-split.h
2014-01-26 23:20:21 +01:00

96 lines
3.5 KiB
C

/*
* Copyright (c) 2004, Swedish Institute of Computer Science.
* 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. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE 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 INSTITUTE 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.
*
* This file is part of the Contiki operating system.
*
* Author: Adam Dunkels <adam@sics.se>
*
*/
/**
* \addtogroup uip
* @{
*/
/**
* \defgroup uipsplit uIP TCP throughput booster hack
* @{
*
* The basic uIP TCP implementation only allows each TCP connection to
* have a single TCP segment in flight at any given time. Because of
* the delayed ACK algorithm employed by most TCP receivers, uIP's
* limit on the amount of in-flight TCP segments seriously reduces the
* maximum achievable throughput for sending data from uIP.
*
* The uip-split module is a hack which tries to remedy this
* situation. By splitting maximum sized outgoing TCP segments into
* two, the delayed ACK algorithm is not invoked at TCP
* receivers. This improves the throughput when sending data from uIP
* by orders of magnitude.
*
* The uip-split module uses the uip-fw module (uIP IP packet
* forwarding) for sending packets. Therefore, the uip-fw module must
* be set up with the appropriate network interfaces for this module
* to work.
*/
/**
* \file
* Module for splitting outbound TCP segments in two to avoid the
* delayed ACK throughput degradation.
* \author
* Adam Dunkels <adam@sics.se>
*
*/
#ifndef UIP_SPLIT_H_
#define UIP_SPLIT_H_
/**
* Handle outgoing packets.
*
* This function inspects an outgoing packet in the uip_buf buffer and
* sends it out using the uip_fw_output() function. If the packet is a
* full-sized TCP segment it will be split into two segments and
* transmitted separately. This function should be called instead of
* the actual device driver output function, or the uip_fw_output()
* function.
*
* The headers of the outgoing packet is assumed to be in the uip_buf
* buffer and the payload is assumed to be wherever uip_appdata
* points. The length of the outgoing packet is assumed to be in the
* uip_len variable.
*
*/
void uip_split_output(void);
#endif /* UIP_SPLIT_H_ */
/** @} */
/** @} */