Repository : ssh://git@open-mesh.org/doc

On branches: backup-redmine/2017-07-13,master

commit 838c4af13360de09666b4ca96263dd5b2795fe05 Author: Sven Eckelmann sven@narfation.org Date: Sat Mar 26 22:14:26 2011 +0000

doc: open-mesh/Gsoc2011-ideas

838c4af13360de09666b4ca96263dd5b2795fe05 open-mesh/Gsoc2011-ideas.textile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/open-mesh/Gsoc2011-ideas.textile b/open-mesh/Gsoc2011-ideas.textile index 064b8e56..cbe947af 100644 --- a/open-mesh/Gsoc2011-ideas.textile +++ b/open-mesh/Gsoc2011-ideas.textile @@ -28,7 +28,7 @@ h4. OGM/NDP Hidden Node Problem Avoidance

Especially in indoor scenarios where corners and thick walls are involved, hidden nodes can be a severe problem. Usually activating RTS/CTS is a common way of solving this problem at least to some degree. However, RTS/CTS can only be applied for unicast packets. Therefore a node sending a lot of data packets to another one, even with RTS/CTS those packets will interfere with BATMAN's broadcast packets (e.g. NDP packets or OGMs). The effect is, that the transmit quality of a node sending NDP packets which does not see the data packet transmission will greatly decrease.

-A suitable solution shall be implemented. This might be based on time slots, multiple interfaces or channel switching and might be implemented within batman-adv or an extra module. See "here":http://www.open-mesh.org/wiki/bcast-hidden-node for a more detailed description of the problem and a solution proposal. +A suitable solution shall be implemented. This might be based on time slots, multiple interfaces or channel switching and might be implemented within batman-adv or an extra module. See [[bcast-hidden-node|here]] for a more detailed description of the problem and a solution proposal.

h4. OGM/NDP Congestion Avoidance @@ -65,7 +65,7 @@ h4. IPv6 Stateless Autoconf Gateway Solution

*Brief description:* Implement a gateway solution for IPv6 stateless autoconfiguration

-batman-adv operates on layer 2, therefore intelligent layer 3 gateway handling is not straightforward. batman-adv currently supports intelligent gateway handling for DHCP (both IPv4 and IPv6), in that it forwards any DHCP discovery or request packet to the best (according to batman's metric) gateway available only, via unicast. However, this is not doable for IPv6 stateless autoconfiguration, as usually not the client is not actively requesting an IP address, but the router is advertising it's gateway capabilities periodically. However, such a stateless configuration is usually more desirable than a stateful configuration as in DHCP in dynamic mesh networks as it allows smoother transitions between subnets and is not as prone to packet loss. Therefore a solution for IPv6 Stateless autoconfiguration shall be implemented. This may be done by exploiting the router preference fields in the router advertisement messages, [http://tools.ietf.org/html/rfc4191 RFC4191":http://www.open-mesh.org/wiki/bcast-hidden-node]., and/or by limiting the range of router advertisements with the help of batman-adv's broadcast packet's TTL field or by introducing a new TQ limit field. A TQ limit field could be dynamically adapted to minimze the overhead of such router advertisements in case of many gateways but ensuring the availability of the best/closest of all gateways in the mesh network. +batman-adv operates on layer 2, therefore intelligent layer 3 gateway handling is not straightforward. batman-adv currently supports intelligent gateway handling for DHCP (both IPv4 and IPv6), in that it forwards any DHCP discovery or request packet to the best (according to batman's metric) gateway available only, via unicast. However, this is not doable for IPv6 stateless autoconfiguration, as usually not the client is not actively requesting an IP address, but the router is advertising it's gateway capabilities periodically. However, such a stateless configuration is usually more desirable than a stateful configuration as in DHCP in dynamic mesh networks as it allows smoother transitions between subnets and is not as prone to packet loss. Therefore a solution for IPv6 Stateless autoconfiguration shall be implemented. This may be done by exploiting the router preference fields in the router advertisement messages, "RFC4191":http://tools.ietf.org/html/rfc4191 , and/or by limiting the range of router advertisements with the help of batman-adv's broadcast packet's TTL field or by introducing a new TQ limit field. A TQ limit field could be dynamically adapted to minimze the overhead of such router advertisements in case of many gateways but ensuring the availability of the best/closest of all gateways in the mesh network.

h4. Improve Broadcast Data Performance