On Saturday, January 16, 2016 16:40:09 Marek Lindner wrote:
From: Linus Luessing linus.luessing@web.de
The B.A.T.M.A.N. protocol originally only used a single message type (called OGM) to determine the link qualities to the direct neighbors and spreading these link quality information through the whole mesh. This procedure is summarized on the BATMAN concept page and explained in details in the RFC draft published in 2008.
This approach was chosen for its simplicity during the protocol design phase and the implementation. However, it also bears some drawbacks:
- Wireless interfaces usually come with some packet loss, therefore a higher broadcast rate is desirable to allow a fast reaction on flaky connections. Other interfaces of the same host might be connected to Ethernet LANs / VPNs / etc which rarely exhibit packet loss would benefit from a lower broadcast rate to reduce overhead.
- It generally is more desirable to detect local link quality changes at a faster rate than propagating all these changes through the entire mesh (the far end of the mesh does not need to care about local link quality changes that much). Other optimizations strategies, like reducing overhead, might be possible if OGMs weren't used for all tasks in the mesh at the same time.
As a result detecting local link qualities shall be handled by an independent message type, ELP, whereas the OGM message type remains responsible for flooding the mesh with these link quality information and determining the overall path transmit qualities.
Developed by Linus during a 6 months trainee study period in Ascom (Switzerland) AG.
Signed-off-by: Linus Luessing linus.luessing@web.de Signed-off-by: Marek Lindner mareklindner@neomailbox.ch Signed-off-by: Antonio Quartulli antonio@open-mesh.com
Makefile | 3 + README.external | 1 + gen-compat-autoconf.sh | 1 + net/batman-adv/Kconfig | 14 ++++ net/batman-adv/Makefile | 2 + net/batman-adv/bat_algo.h | 15 +++- net/batman-adv/bat_v.c | 74 +++++++++++++++++ net/batman-adv/bat_v_elp.c | 193 +++++++++++++++++++++++++++++++++++++++++++++ net/batman-adv/bat_v_elp.h | 27 +++++++ net/batman-adv/main.c | 1 + net/batman-adv/packet.h | 20 +++++ net/batman-adv/types.h | 18 +++++ 12 files changed, 368 insertions(+), 1 deletion(-) create mode 100644 net/batman-adv/bat_v.c create mode 100644 net/batman-adv/bat_v_elp.c create mode 100644 net/batman-adv/bat_v_elp.h
Applied in revision a4b88af.
Thanks, Marek