linux/net/batman-adv
Antonio Quartulli a73105b8d4 batman-adv: improved client announcement mechanism
The client announcement mechanism informs every mesh node in the network
of any connected non-mesh client, in order to find the path towards that
client from any given point in the mesh.

The old implementation was based on the simple idea of appending a data
buffer to each OGM containing all the client MAC addresses the node is
serving. All other nodes can populate their global translation tables
(table which links client MAC addresses to node addresses) using this
MAC address buffer and linking it to the node's address contained in the
OGM. A node that wants to contact a client has to lookup the node the
client is connected to and its address in the global translation table.

It is easy to understand that this implementation suffers from several
issues:
 - big overhead (each and every OGM contains the entire list of
   connected clients)
 - high latencies for client route updates due to long OGM trip time and
   OGM losses

The new implementation addresses these issues by appending client
changes (new client joined or a client left) to the OGM instead of
filling it with all the client addresses each time. In this way nodes
can modify their global tables by means of "updates", thus reducing the
overhead within the OGMs.

To keep the entire network in sync each node maintains a translation
table version number (ttvn) and a translation table checksum. These
values are spread with the OGM to allow all the network participants to
determine whether or not they need to update their translation table
information.

When a translation table lookup is performed in order to send a packet
to a client attached to another node, the destination's ttvn is added to
the payload packet. Forwarding nodes can compare the packet's ttvn with
their destination's ttvn (this node could have a fresher information
than the source) and re-route the packet if necessary. This greatly
reduces the packet loss of clients roaming from one AP to the next.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-06-20 11:37:24 +02:00
..
aggregation.c batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
aggregation.h batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
bat_debugfs.c batman-adv: Calculate sizeof using variable insead of types 2011-05-30 07:39:33 +02:00
bat_debugfs.h batman-adv: Update copyright years 2011-01-31 14:57:12 +01:00
bat_sysfs.c batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
bat_sysfs.h batman-adv: Update copyright years 2011-01-31 14:57:12 +01:00
bitarray.c batman-adv: Reduce usage of char 2011-06-20 11:37:18 +02:00
bitarray.h batman-adv: Reduce usage of char 2011-06-20 11:37:18 +02:00
gateway_client.c batman-adv: Reduce usage of char 2011-06-20 11:37:18 +02:00
gateway_client.h batman-adv: concentrate all curr_gw related rcu operations in select/deselect functions 2011-04-17 21:11:01 +02:00
gateway_common.c batman-adv: Reduce usage of char 2011-06-20 11:37:18 +02:00
gateway_common.h batman-adv: Update copyright years 2011-01-31 14:57:12 +01:00
hard-interface.c batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
hard-interface.h batman-adv: Use enums for related constants 2011-06-09 20:40:38 +02:00
hash.c batman-adv: Calculate sizeof using variable insead of types 2011-05-30 07:39:33 +02:00
hash.h batman-adv: Add const type qualifier for pointers 2011-05-30 07:39:31 +02:00
icmp_socket.c batman-adv: Calculate sizeof using variable insead of types 2011-05-30 07:39:33 +02:00
icmp_socket.h batman-adv: Remove duplicate types.h inclusions 2011-02-11 23:30:29 +01:00
Kconfig batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
main.c batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
main.h batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
Makefile batman-adv: Update copyright years 2011-01-31 14:57:12 +01:00
originator.c batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
originator.h batman-adv: Move compare_orig to originator.c 2011-06-20 10:38:55 +02:00
packet.h batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
ring_buffer.c batman-adv: Add const type qualifier for pointers 2011-05-30 07:39:31 +02:00
ring_buffer.h batman-adv: Add const type qualifier for pointers 2011-05-30 07:39:31 +02:00
routing.c batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
routing.h batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
send.c batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
send.h batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
soft-interface.c batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
soft-interface.h batman-adv: Keep interface_tx as local function 2011-06-20 10:38:59 +02:00
translation-table.c batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
translation-table.h batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
types.h batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
unicast.c batman-adv: improved client announcement mechanism 2011-06-20 11:37:24 +02:00
unicast.h batman-adv: Calculate sizeof using variable insead of types 2011-05-30 07:39:33 +02:00
vis.c batman-adv: move smallest_signed_int(), seq_before() and seq_after() into main.h 2011-05-30 07:39:35 +02:00
vis.h batman-adv: Update copyright years 2011-01-31 14:57:12 +01:00