X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/a79a8e1cab86ccc687cfbc97b01b735acb996f16..befbbbe1fbb31663a8f91e24ce12df271cf4ae79:/src/kernel/routing/VivaldiZone.hpp

diff --git a/src/kernel/routing/VivaldiZone.hpp b/src/kernel/routing/VivaldiZone.hpp
index 56da872f31..9b7c9ffb00 100644
--- a/src/kernel/routing/VivaldiZone.hpp
+++ b/src/kernel/routing/VivaldiZone.hpp
@@ -1,4 +1,4 @@
-/* Copyright (c) 2013-2016. The SimGrid Team. All rights reserved.          */
+/* Copyright (c) 2013-2017. The SimGrid Team. All rights reserved.          */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
@@ -12,20 +12,50 @@ namespace simgrid {
 namespace kernel {
 namespace routing {
 
-/* This extends cluster because each host has a private link */
+/** @ingroup ROUTING_API
+ *  @brief NetZone modeling peers connected to the cloud through a private link
+ *
+ *  This netzone model is particularly well adapted to Peer-to-Peer and Clouds platforms:
+ *  each component is connected to the cloud through a private link of which the upload
+ *  and download rate may be asymmetric.
+ *
+ *  The network core (between the private links) is assumed to be over-sized so only the
+ *  latency is taken into account. Instead of a matrix of latencies that would become too
+ *  large when the amount of peers grows, Vivaldi netzones give a coordinate to each peer
+ *  and compute the latency between host A=(xA,yA,zA) and host B=(xB,yB,zB) as follows:
+ *
+ *   latency = sqrt( (xA-xB)² + (yA-yB)² ) + zA + zB
+ *
+ *  The resulting value is assumed to be in milliseconds.
+ *
+ *  So, to go from an host A to an host B, the following links would be used:
+ *  <tt>private(A)_UP, private(B)_DOWN</tt>, with the additional latency computed above.
+ *  The bandwidth of the UP and DOWN links is not symmetric (in contrary to usual SimGrid
+ *  links), but naturally correspond to the values provided when the peer was created.
+ *  More information in the relevant section of the XML reference guide: @ref pf_peer.
+ *
+ *  You can find some Coordinate-based platforms from the OptorSim project, as well as a
+ *  script to turn them into SimGrid platforms in examples/platforms/syscoord.
+ *
+ *  Such Network Coordinate systems were shown to provide rather good latency estimations
+ *  in a compact way. Other systems, such as
+ *  <a href="https://en.wikipedia.org/wiki/Phoenix_network_coordinates"Phoenix network coordinates</a>
+ *  were shown superior to the Vivaldi system and could be also implemented in SimGrid.
+ */
+
 class XBT_PRIVATE VivaldiZone : public ClusterZone {
 public:
   explicit VivaldiZone(NetZone* father, const char* name);
 
-  void setPeerLink(NetCard* netcard, double bw_in, double bw_out, double lat, const char* coord);
-  void getLocalRoute(NetCard* src, NetCard* dst, sg_platf_route_cbarg_t into, double* latency) override;
+  void setPeerLink(NetPoint* netpoint, double bw_in, double bw_out, const char* coord);
+  void getLocalRoute(NetPoint* src, NetPoint* dst, sg_platf_route_cbarg_t into, double* latency) override;
 };
 
 namespace vivaldi {
 class XBT_PRIVATE Coords {
 public:
-  static simgrid::xbt::Extension<NetCard, Coords> EXTENSION_ID;
-  explicit Coords(NetCard* host, const char* str);
+  static simgrid::xbt::Extension<NetPoint, Coords> EXTENSION_ID;
+  explicit Coords(NetPoint* host, const char* str);
   virtual ~Coords();
 
   std::vector<double> coords;