/* * OpenVPN -- An application to securely tunnel IP networks * over a single TCP/UDP port, with support for SSL/TLS-based * session authentication and key exchange, * packet encryption, packet authentication, and * packet compression. * * Copyright (C) 2010-2018 Fox Crypto B.V. * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ /** * @file * Reliability Layer module documentation file. */ /** * @defgroup reliable Reliability Layer module * * The Reliability Layer is part of OpenVPN's control channel. It * provides a reliable and sequential transport mechanism for control * channel messages between OpenVPN peers. This module forms the * interface between the \link external_multiplexer External * Multiplexer\endlink and the \link control_tls Control Channel TLS * module\endlink. * * @par UDP or TCP as VPN tunnel transport * * This is especially important when OpenVPN is configured to communicate * over UDP, because UDP does not offer a reliable and sequential * transport. OpenVPN endpoints can also communicate over TCP which does * provide a reliable and sequential transport. In both cases, using UDP * or TCP as an external transport, the internal Reliability Layer is * active. */