1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */ 2 /* 3 * Copyright (c) 2014 Natale Patriciello, <natale.patriciello@gmail.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation; 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 17 * 18 */ 19 20 #ifndef TCPHIGHSPEED_H 21 #define TCPHIGHSPEED_H 22 23 #include "tcp-congestion-ops.h" 24 25 namespace ns3 { 26 27 class TcpSocketState; 28 29 /** 30 * \ingroup congestionOps 31 * 32 * \brief An implementation of TCP HighSpeed 33 * 34 * TCP HighSpeed is designed for high-capacity channels or, in general, for 35 * TCP connections with large congestion windows. 36 * Conceptually, with respect to the standard TCP, HighSpeed makes the 37 * cWnd grow faster during the probing phases and accelerates the 38 * cWnd recovery from losses. 39 * This behavior is executed only when the window grows beyond a 40 * certain threshold, which allows TCP Highspeed to be friendly with standard 41 * TCP in environments with heavy congestion, without introducing new dangers 42 * of congestion collapse. 43 * At the core of TCP HighSpeed there are two functions, a(w) and b(w), which respectively 44 * specify the cWnd growth addendum and the cWnd reduction factor when 45 * given an actual cWnd value w. 46 * 47 * More information: http://dl.acm.org/citation.cfm?id=2756518 48 */ 49 class TcpHighSpeed : public TcpNewReno 50 { 51 public: 52 /** 53 * \brief Get the type ID. 54 * \return the object TypeId 55 */ 56 static TypeId GetTypeId (void); 57 58 /** 59 * Create an unbound tcp socket. 60 */ 61 TcpHighSpeed (void); 62 63 /** 64 * \brief Copy constructor 65 * \param sock the object to copy 66 */ 67 TcpHighSpeed (const TcpHighSpeed& sock); 68 virtual ~TcpHighSpeed (void); 69 70 virtual std::string GetName () const; 71 72 virtual uint32_t GetSsThresh (Ptr<const TcpSocketState> tcb, 73 uint32_t bytesInFlight); 74 75 virtual Ptr<TcpCongestionOps> Fork (); 76 77 /** 78 * \brief Lookup table for the coefficient a (from RFC 3649) 79 * 80 * \param w Window value (in packets) 81 * 82 * \return the coefficient a 83 */ 84 static uint32_t TableLookupA (uint32_t w); 85 86 /** 87 * \brief Lookup table for the coefficient b (from RFC 3649) 88 * 89 * \param w Window value (in packets) 90 * 91 * \return the coefficient b 92 */ 93 static double TableLookupB (uint32_t w); 94 95 protected: 96 virtual void CongestionAvoidance (Ptr<TcpSocketState> tcb, uint32_t segmentsAcked); 97 98 private: 99 uint32_t m_ackCnt; //!< Number of received ACK, corrected with the coefficient a 100 }; 101 102 } // namespace ns3 103 104 #endif // TCPHIGHSPEED_H 105