Repository : ssh://git@open-mesh.org/doc
On branches: backup-redmine/2017-07-13,master
commit d8bb0115cc10c945e6ef5818d845d54fab5c6941 Author: Antonio Quartulli a@unstable.cc Date: Mon May 2 09:40:50 2011 +0000
doc: batman-adv/Client-announcement
d8bb0115cc10c945e6ef5818d845d54fab5c6941 batman-adv/Client-announcement.textile | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)
diff --git a/batman-adv/Client-announcement.textile b/batman-adv/Client-announcement.textile new file mode 100644 index 00000000..0fcc0745 --- /dev/null +++ b/batman-adv/Client-announcement.textile @@ -0,0 +1,30 @@ +h1. Client-announcement + +The development branch is at http://git.open-mesh.org/?p=ordex/batman-adv.git;a=shortlog;h=refs/heads/hna... + + +h2. Current Contstraints of client announcement + +Up until recently, BATMAN-Adv. was mostly used to build a mesh network and to allow communitcation between BATMAN-Adv. nodes or a few hosts being bridged into the mesh through certain nodes. However, the desire to also use BATMAN-Adv. to interconnect a larger, common, wired LAN with Wifi access points for client devices into a single subnet has increased. The current implementation just adds the clients' mac addresses to the responsible nodes OGMs - so called HNAs (host network announcements) which has three constraints: +* A lot of overhead even when the HNAs do not change. +* The amount of HNAs per OGM is quite limited and does not work when bridging larger LANs into the mesh cloud. +* It can take up to a couple of seconds for a node to roam and being recognised at its new position, depending on the link qualities. A unicast packet send to the outdated orignator will just be dropped at this node. + + +h2. Concept Ideas + +h3. How the announcement works + +* Instead of adding all client MAC addresses, the OGM packet format has been modified to include: +** a local translation table reference ID (TT version number); +** a set of local translation table changes which happened in the last OGM interval +* When a node local translation table changes at least once in one OGM interval (added or (re)moved client), increase TT version number by one. +* If a node receives an OGM with a newer, higher ref.-ID, it updates its global translation table with the set of changes carried by the OGM. +** if an OGM was missed (we have a gap in the changes list), then the node must queries the originator for an update with a special unicast packet: TT-REQUEST +* Any node on the paths between the querier and the destination may decide to not forward the TT-REQUEST and answer it by itself if it already has the needed changes. => This avoids a storm of unicast packets towards the destination after its local translation table changes. + +* Every node memorizes the last changeset announced within the OGM of each node in the network +* A TT-REQUEST can request a complete local table or just a the last sent changeset. + +Notes: +A research project has been done on this topic and it will be linked on this page as soon as it get ready. \ No newline at end of file