diff --git a/src/routing/global-routing/global-routing.h b/src/routing/global-routing/global-routing.h new file mode 100644 index 000000000..ad9851505 --- /dev/null +++ b/src/routing/global-routing/global-routing.h @@ -0,0 +1,79 @@ +/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */ +/* + * Copyright 2008 University of Washington + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +/** + * \ingroup routing + * \defgroup globalrouting Global Routing + * + * \section model Model + * + * ns-3 global routing performs pre-simulation static route computation + * on a layer-3 Ipv4 topology. The user API from the script level is + * fairly minimal; once a topology has been constructed and addresses + * assigned, the user may call ns3::GlobalRouteManager::PopulateRoutingTables() + * and the simulator will initialize the routing database and set up + * static unicast forwarding tables for each node. + * + * The model assumes that all nodes on an ns-3 channel are reachable to + * one another, regardless of whether the nodes can use the channel + * successfully (in the case of wireless). Therefore, this model + * should typically be used only on wired topologies. API does not + * yet exist to control the subset of a topology to which this global + * static routing is applied. + * + * This model also does not yet deal with the possible presence of + * layer-2 relays such as switches, bridges, and hubs, although ns-3 does + * not have such devices yet. + * + * \section api API and Usage + * + * Users must include ns3/global-route-manager.h header file. After the + * IPv4 topology has been built and addresses assigned, users call + * ns3::GlobalRouteManager::PopulateRoutingTables (), prior to the + * ns3::Simulator::Run() call. There are no other attributes or + * public methods that are typically called, or ways to parameterize + * the behavior. + * + * \section impl Implementation + * + * A singleton object, ns3::GlobalRouteManager, builds a global routing + * database of information about the topology, and executes a Dijkstra + * Shortest Path First (SPF) algorithm on the topology for each node, and + * stores the computed routes in each node's IPv4 forwarding table by + * making use of the routing API in class ns3::Ipv4. + * + * The nodes that export data are those that have had an ns3::GlobalRouter + * object aggregated to them. The ns3::GlobalRouter can be thought of + * as a per-node agent that exports topology information to the + * ns3::GlobalRouteManager. When it comes time to build the global + * routing database, the list of nodes is iterated and each node with + * an ns3::GlobalRouter object is asked to export routing information + * concerning the links to which it is attached. + * + * The format of the data exported conforms to the OSPFv2 standard + * (http://www.ietf.org/rfc/rfc2328.txt). In particular, the + * information is exported in the form of ns3::GlobalLSA objects that + * semantically match the Link State Advertisements of OSPF. + * + * By using a standard data format for reporting topology, existing + * OSPF route computation code can be reused, and that is what is done + * by the ns3::GlobalRouteManager. The main computation functions are + * ported from the quagga routing suite (http://www.quagga.net). + * + */