Eric Lee / smarc-fsl-linux-kernel

08 Sep, 2011

2 commits

20 Jun, 2011

2 commits

  • cc47f66e6   batman-adv: improved roaming mechanism ... Browse Code »

    With the current client announcement implementation, in case of roaming,
    an update is triggered on the new AP serving the client. At that point
    the new information is spread around by means of the OGM broadcasting
    mechanism. Until this operations is not executed, no node is able to
    correctly route traffic towards the client. This obviously causes packet
    drops and introduces a delay in the time needed by the client to recover
    its connections.

    A new packet type called ROAMING_ADVERTISEMENT is added to account this
    issue.

    This message is sent in case of roaming from the new AP serving the
    client to the old one and will contain the client MAC address. In this
    way an out-of-OGM update is immediately committed, so that the old node
    can update its global translation table. Traffic reaching this node will
    then be redirected to the correct destination utilising the fresher
    information. Thus reducing the packet drops and the connection recovery
    delay.

    Signed-off-by: Antonio Quartulli
    Signed-off-by: Sven Eckelmann

    Antonio Quartulli
     
  • a73105b8d   batman-adv: improved client announcement mechanism ... Browse Code »
    43

    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
    Signed-off-by: Marek Lindner
    Signed-off-by: Sven Eckelmann

    Antonio Quartulli
     

30 May, 2011

1 commit

08 May, 2011

1 commit

05 Mar, 2011

3 commits

12 Feb, 2011

1 commit

31 Jan, 2011

2 commits

17 Dec, 2010

1 commit

  • c6c8fea29   net: Add batman-adv meshing protocol ... Browse Code »

    B.A.T.M.A.N. (better approach to mobile ad-hoc networking) is a routing
    protocol for multi-hop ad-hoc mesh networks. The networks may be wired or
    wireless. See http://www.open-mesh.org/ for more information and user space
    tools.

    Signed-off-by: Sven Eckelmann
    Signed-off-by: David S. Miller

    Sven Eckelmann