i have a question ? How many relay nodes can be supported at NetworkCoding ( mtu 1546 ) .

i have a question ? How many relay nodes can be supported at NetworkCoding ( mtu 1546 ) .

[johnzeng]

Hello Dear Sir :

i read some detail about NetworkCoding , my understanding :

every relay node will detects neighbors packet at promisc mode and
combine these packet into a single transmission ,

and every relay mode will keep some usaful ( Ingoing: c8:3a:35:c9:ce:71
.... ) and they will add some encoded information into packet
( will send destination )

So we will run the part --- ip link set dev wlan0 mtu 1546 ( more than
1532 )

but i have a question ? How many relay nodes can be supported at
NetworkCoding ( mtu 1546 ) .


Thanks

Tiger

batctl nn
Node: c8:3a:35:c9:ce:71
Ingoing: c8:3a:35:c9:ce:71
Outgoing: c8:3a:35:c9:ce:71

[root@alarmpi ~]# batctl nc
enabled


[root@alarmpi ~]# batctl statistics
tx: 18
tx_bytes: 2076
tx_dropped: 32
rx: 767
rx_bytes: 33993
forward: 0
forward_bytes: 0
mgmt_tx: 7956
mgmt_tx_bytes: 542012
mgmt_rx: 3132
mgmt_rx_bytes: 222572
frag_tx: 0
frag_tx_bytes: 0
frag_rx: 0
frag_rx_bytes: 0
frag_fwd: 0
frag_fwd_bytes: 0
tt_request_tx: 0
tt_request_rx: 1
tt_response_tx: 1
tt_response_rx: 0
tt_roam_adv_tx: 0
tt_roam_adv_rx: 0
dat_get_tx: 2
dat_get_rx: 0
dat_put_tx: 0
dat_put_rx: 4
dat_cached_reply_tx: 0
nc_code: 0
nc_code_bytes: 0
nc_recode: 0
nc_recode_bytes: 0
nc_buffer: 17
nc_decode: 0
nc_decode_bytes: 0
nc_decode_failed: 0
nc_sniffed: 0

Re: i have a question ? How many relay nodes can be supported at NetworkCoding ( mtu 1546 ) .

[johnzeng]

Hello Dear Sir:

if anybody know the part , please give me some advisement .

Thanks
>
> Hello Dear Sir :
>
> i read some detail about NetworkCoding , my understanding :
>
> every relay node will detects neighbors packet at promisc mode and
> combine these packet into a single transmission ,
>
> and every relay mode will keep some usaful ( Ingoing: c8:3a:35:c9:ce:71
> .... ) and they will add some encoded information into packet
> ( will send destination )
>
> So we will run the part --- ip link set dev wlan0 mtu 1546 ( more than
> 1532 )
>
> but i have a question ? How many relay nodes can be supported at
> NetworkCoding ( mtu 1546 ) .
>
>
> Thanks
>
> Tiger
>
> batctl nn
> Node: c8:3a:35:c9:ce:71
> Ingoing: c8:3a:35:c9:ce:71
> Outgoing: c8:3a:35:c9:ce:71
>
> [root@alarmpi ~]# batctl nc
> enabled
>
>
> [root@alarmpi ~]# batctl statistics
> tx: 18
> tx_bytes: 2076
> tx_dropped: 32
> rx: 767
> rx_bytes: 33993
> forward: 0
> forward_bytes: 0
> mgmt_tx: 7956
> mgmt_tx_bytes: 542012
> mgmt_rx: 3132
> mgmt_rx_bytes: 222572
> frag_tx: 0
> frag_tx_bytes: 0
> frag_rx: 0
> frag_rx_bytes: 0
> frag_fwd: 0
> frag_fwd_bytes: 0
> tt_request_tx: 0
> tt_request_rx: 1
> tt_response_tx: 1
> tt_response_rx: 0
> tt_roam_adv_tx: 0
> tt_roam_adv_rx: 0
> dat_get_tx: 2
> dat_get_rx: 0
> dat_put_tx: 0
> dat_put_rx: 4
> dat_cached_reply_tx: 0
> nc_code: 0
> nc_code_bytes: 0
> nc_recode: 0
> nc_recode_bytes: 0
> nc_buffer: 17
> nc_decode: 0
> nc_decode_bytes: 0
> nc_decode_failed: 0
> nc_sniffed: 0

Re: [B.A.T.M.A.N.] i have a question ? How many relay nodes can be supported at NetworkCoding ( mtu 1546 ) .

[Sven Eckelmann]

[-- Attachment #1: Type: text/plain, Size: 4476 bytes --]

Hi,

> When i compile the part , whether i need make
> CONFIG_BATMAN_ADV_BATMAN_V=y at batman-adv-2016.2

2016.2 is "old". And BATMAN_V has nothing to do with network coding.

> i read some detail about NetworkCoding , my understanding :
> 
> every relay node will detects neighbors packet at promisc mode and
> combine these packet into a single transmission ,

I think Martin can help here. He also provided some documentation:

* https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding
* https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding-technical
* https://downloads.open-mesh.org/batman/papers/batman-adv_network_coding.pdf
* https://vbn.aau.dk/da/publications/catwoman(214ee21a-e786-495d-85c9-3efac4718ead).html
* https://downloads.open-mesh.org/batman/misc/wbmv4-network_coding.avi

And it will not try to forward each packet is overheard. Instead it
will try to find coding opportunities which it then uses to forward
its own packets in less transmissions (by using packets which the
other nodes should already know).

>               batctl nc 1
>               echo 1 > /sys/class/net/bat0/mesh/network_coding
>               ip link set dev wlan0 promisc on
>               ip link set dev wlan0 mtu 1546

Your cards/drivers will most likely not even support promiscuous mode.
Some of them require to have an monitor mode interface at the same time and
some of them will simply not work.

You can test it by simply checking what tcpdump is showing you on the
underlying interface (wlan0). If it doesn't show you the packets between
two other nodes then promiscuous mode is not working for you.

The feature itself is not used very often (Martin, please correct me here).
It is not enabled by default because it is not making things "better" all
the time [1]. So it is also not tested as much as other components in
batman-adv and you should think first if it is really useful for your
scenario/HW. I knew at least from some Freifunk communities played around
when it was enabled by default but had to revert when they experienced "non
functional mesh links" (nothing more about it is known to me - sorry Martin).


> if i send a packet from host A to hostC via hostB, whether hostB will
> open relay mode at layer2 .

I completely failed to parse this.

batman-adv will send your data from hostA to hostC via hostB when the TQ
value for the link "from hostA to hostC via hostB" is higher than the TQ
value for the link "hostA to hostC directly". This has nothing to do with
network coding and is a standard feature of batman-adv (this is actually
what it is about).

network coding can only (when lucky) try to combine some packets - but
this will only work when promiscuous mode is actually working and the
nodes can overhear packets. Otherwise it will (in theory - Martin please
correct me if I overlooked a safety mechanism) just create a lot of coded
packets which cannot be decoded anymore. This seems to be especially
problematic when some nodes are for example 2x2 MIMO devices and others
are 3x3. At least this would be a good way to let the 2x2 miss important
packets when the 3x3 devices talk between each other.

I would even guess that things like dynamic transmission power would make
overhearing packets also more problematic.

> but i have a question ? How many relay nodes can be supported at
> NetworkCoding ( mtu 1546 ) .

I am not sure what you are asking here. The implementation in batman-adv
can combine two packets into one. And this combining of these two packets
is done by exact one relay node. The decoding is done by the two receiving
nodes. What you can build with it is been shown in the documentation from
Martin. The network coding used here is therefore done by a relay node and
its neighbors. But there can be multiple relay nodes in the mesh doing
network coding at the same time.


I personally haven't used network coding with batman-adv. But since you've
created multiple new threads on the mailing list [1,2,3,4] (beside the
private mail *grml*) - here is at least a pseudo-answer.

Kind regards,
	Sven

[1] https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding#Drawbacks
[2] https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016586.html
[3] https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016587.html
[4] https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016588.html
[5] https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016592.html

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Re: i have a question ? How many relay nodes can be supported at NetworkCoding ( mtu 1546 ) .

[Martin Hundebøll]

Hi,

On 2016-11-05 15:28, Sven Eckelmann wrote:
> Hi,
>
>> When i compile the part , whether i need make
>> CONFIG_BATMAN_ADV_BATMAN_V=y at batman-adv-2016.2
>
> 2016.2 is "old". And BATMAN_V has nothing to do with network coding.
>
>> i read some detail about NetworkCoding , my understanding :
>>
>> every relay node will detects neighbors packet at promisc mode and
>> combine these packet into a single transmission ,
>
> I think Martin can help here. He also provided some documentation:
>
> * https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding
> * https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding-technical
> * https://downloads.open-mesh.org/batman/papers/batman-adv_network_coding.pdf
> * https://vbn.aau.dk/da/publications/catwoman(214ee21a-e786-495d-85c9-3efac4718ead).html
> * https://downloads.open-mesh.org/batman/misc/wbmv4-network_coding.avi

If you are looking into network coding as a research project, batman-adv 
is a fine starting point. But as Sven hinted in his answer, it isn't 
really useful in a real setup.

> And it will not try to forward each packet is overheard. Instead it
> will try to find coding opportunities which it then uses to forward
> its own packets in less transmissions (by using packets which the
> other nodes should already know).
>
>>               batctl nc 1
>>               echo 1 > /sys/class/net/bat0/mesh/network_coding
>>               ip link set dev wlan0 promisc on
>>               ip link set dev wlan0 mtu 1546
>
> Your cards/drivers will most likely not even support promiscuous mode.
> Some of them require to have an monitor mode interface at the same time and
> some of them will simply not work.
>
> You can test it by simply checking what tcpdump is showing you on the
> underlying interface (wlan0). If it doesn't show you the packets between
> two other nodes then promiscuous mode is not working for you.
>
> The feature itself is not used very often (Martin, please correct me here).

I don't use it myself, and don't know of anyone else using it.

> It is not enabled by default because it is not making things "better" all
> the time [1]. So it is also not tested as much as other components in
> batman-adv and you should think first if it is really useful for your
> scenario/HW. I knew at least from some Freifunk communities played around
> when it was enabled by default but had to revert when they experienced "non
> functional mesh links" (nothing more about it is known to me - sorry Martin).

No problem.

[snip...]

> network coding can only (when lucky) try to combine some packets - but
> this will only work when promiscuous mode is actually working and the
> nodes can overhear packets. Otherwise it will (in theory - Martin please
> correct me if I overlooked a safety mechanism) just create a lot of coded
> packets which cannot be decoded anymore.

Yeah, packets are lost if the nodes are not promiscuous.

Good luck with the project :)

// Martin

Re: i have a question ? How many relay nodes can be supported at NetworkCoding ( mtu 1546 ) .

[johnzeng]

Hello Dear Sven and Martin:

                                              Thanks for your advisement

                                              I hope to aviod Excavation 
of underground pipeline in the smart community or Park .

                                              if Batman-adv can support 
smart relay ( networking code ) at mesh network really , and it will be 
very valuable for us .

                                              i think one of  core 
valuable point is  relay mode   and   Client roaming

                                              i prepare to build more ap 
evironment and test for the part  later




As market competition intensifies,

                                              the gap between similar 
productsis getting smaller and smaller,

                                              likewise the evolution of 
growing homogenization trends within the industry.



                                              i hope we can find 
valuable point for Blue Ocean each other .

                                              if you have some different 
point , and I would be happy to be the first and build win-win mode each 
other .


                                              Best Regards

                                               Tiger





> Hi,
>
>> When i compile the part , whether i need make
>> CONFIG_BATMAN_ADV_BATMAN_V=y at batman-adv-2016.2
> 2016.2 is "old". And BATMAN_V has nothing to do with network coding.
>
>> i read some detail about NetworkCoding , my understanding :
>>
>> every relay node will detects neighbors packet at promisc mode and
>> combine these packet into a single transmission ,
> I think Martin can help here. He also provided some documentation:
>
> * https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding
> * https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding-technical
> * https://downloads.open-mesh.org/batman/papers/batman-adv_network_coding.pdf
> * https://vbn.aau.dk/da/publications/catwoman(214ee21a-e786-495d-85c9-3efac4718ead).html
> * https://downloads.open-mesh.org/batman/misc/wbmv4-network_coding.avi
>
> And it will not try to forward each packet is overheard. Instead it
> will try to find coding opportunities which it then uses to forward
> its own packets in less transmissions (by using packets which the
> other nodes should already know).
>
>>                batctl nc 1
>>                echo 1 > /sys/class/net/bat0/mesh/network_coding
>>                ip link set dev wlan0 promisc on
>>                ip link set dev wlan0 mtu 1546
> Your cards/drivers will most likely not even support promiscuous mode.
> Some of them require to have an monitor mode interface at the same time and
> some of them will simply not work.
>
> You can test it by simply checking what tcpdump is showing you on the
> underlying interface (wlan0). If it doesn't show you the packets between
> two other nodes then promiscuous mode is not working for you.
>
> The feature itself is not used very often (Martin, please correct me here).
> It is not enabled by default because it is not making things "better" all
> the time [1]. So it is also not tested as much as other components in
> batman-adv and you should think first if it is really useful for your
> scenario/HW. I knew at least from some Freifunk communities played around
> when it was enabled by default but had to revert when they experienced "non
> functional mesh links" (nothing more about it is known to me - sorry Martin).
>
>
>> if i send a packet from host A to hostC via hostB, whether hostB will
>> open relay mode at layer2 .
> I completely failed to parse this.
>
> batman-adv will send your data from hostA to hostC via hostB when the TQ
> value for the link "from hostA to hostC via hostB" is higher than the TQ
> value for the link "hostA to hostC directly". This has nothing to do with
> network coding and is a standard feature of batman-adv (this is actually
> what it is about).
>
> network coding can only (when lucky) try to combine some packets - but
> this will only work when promiscuous mode is actually working and the
> nodes can overhear packets. Otherwise it will (in theory - Martin please
> correct me if I overlooked a safety mechanism) just create a lot of coded
> packets which cannot be decoded anymore. This seems to be especially
> problematic when some nodes are for example 2x2 MIMO devices and others
> are 3x3. At least this would be a good way to let the 2x2 miss important
> packets when the 3x3 devices talk between each other.
>
> I would even guess that things like dynamic transmission power would make
> overhearing packets also more problematic.
>
>> but i have a question ? How many relay nodes can be supported at
>> NetworkCoding ( mtu 1546 ) .
> I am not sure what you are asking here. The implementation in batman-adv
> can combine two packets into one. And this combining of these two packets
> is done by exact one relay node. The decoding is done by the two receiving
> nodes. What you can build with it is been shown in the documentation from
> Martin. The network coding used here is therefore done by a relay node and
> its neighbors. But there can be multiple relay nodes in the mesh doing
> network coding at the same time.
>
>
> I personally haven't used network coding with batman-adv. But since you've
> created multiple new threads on the mailing list [1,2,3,4] (beside the
> private mail *grml*) - here is at least a pseudo-answer.
>
> Kind regards,
> 	Sven
>
> [1] https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding#Drawbacks
> [2] https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016586.html
> [3] https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016587.html
> [4] https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016588.html
> [5] https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016592.html

Re: [B.A.T.M.A.N.] i have a question ? How many relay nodes can be supported at NetworkCoding ( mtu 1546 ) .

[Simon Wunderlich]

[-- Attachment #1: Type: text/plain, Size: 6733 bytes --]

On Tuesday, November 8, 2016 11:55:14 AM CET johnzeng via B.A.T.M.A.N wrote:
> Hello Dear Sven and Martin:
> 
>                                               Thanks for your advisement
> 
>                                               I hope to aviod Excavation 
> of underground pipeline in the smart community or Park .
> 
>                                               if Batman-adv can support 
> smart relay ( networking code ) at mesh network really , and it will be 
> very valuable for us .

Hi Johnzeng,

why are you insisting on using network coding? Batman-adv can do relay without 
network coding enabled, this is part of the basic mesh technology. Network 
Coding (or CATWOMAN) was research project/proof of concept implementation 
which isn't actively maintained right now. But from what I understood, your 
setups can be supported with "standard" batman-adv mesh.

Thanks,
    Simon 

> 
>                                               i think one of  core 
> valuable point is  relay mode   and   Client roaming
> 
>                                               i prepare to build more ap 
> evironment and test for the part  later
> 
> 
> 
> 
> As market competition intensifies,
> 
>                                               the gap between similar 
> productsis getting smaller and smaller,
> 
>                                               likewise the evolution of 
> growing homogenization trends within the industry.
> 
> 
> 
>                                               i hope we can find 
> valuable point for Blue Ocean each other .
> 
>                                               if you have some different 
> point , and I would be happy to be the first and build win-win mode each 
> other .
> 
> 
>                                               Best Regards
> 
>                                                Tiger
> 
> > Hi,
> > 
> >> When i compile the part , whether i need make
> >> CONFIG_BATMAN_ADV_BATMAN_V=y at batman-adv-2016.2
> > 
> > 2016.2 is "old". And BATMAN_V has nothing to do with network coding.
> > 
> >> i read some detail about NetworkCoding , my understanding :
> >> 
> >> every relay node will detects neighbors packet at promisc mode and
> >> combine these packet into a single transmission ,
> > 
> > I think Martin can help here. He also provided some documentation:
> > 
> > * https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding
> > *
> > https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding-technica
> > l *
> > https://downloads.open-mesh.org/batman/papers/batman-adv_network_coding.p
> > df *
> > https://vbn.aau.dk/da/publications/catwoman(214ee21a-e786-495d-85c9-3efac
> > 4718ead).html *
> > https://downloads.open-mesh.org/batman/misc/wbmv4-network_coding.avi
> > 
> > And it will not try to forward each packet is overheard. Instead it
> > will try to find coding opportunities which it then uses to forward
> > its own packets in less transmissions (by using packets which the
> > other nodes should already know).
> > 
> >> batctl nc 1
> >> echo 1 > /sys/class/net/bat0/mesh/network_coding
> >> ip link set dev wlan0 promisc on
> >> ip link set dev wlan0 mtu 1546
> > 
> > Your cards/drivers will most likely not even support promiscuous mode.
> > Some of them require to have an monitor mode interface at the same time
> > and
> > some of them will simply not work.
> > 
> > You can test it by simply checking what tcpdump is showing you on the
> > underlying interface (wlan0). If it doesn't show you the packets between
> > two other nodes then promiscuous mode is not working for you.
> > 
> > The feature itself is not used very often (Martin, please correct me
> > here).
> > It is not enabled by default because it is not making things "better" all
> > the time [1]. So it is also not tested as much as other components in
> > batman-adv and you should think first if it is really useful for your
> > scenario/HW. I knew at least from some Freifunk communities played around
> > when it was enabled by default but had to revert when they experienced
> > "non
> > functional mesh links" (nothing more about it is known to me - sorry
> > Martin).> 
> >> if i send a packet from host A to hostC via hostB, whether hostB will
> >> open relay mode at layer2 .
> > 
> > I completely failed to parse this.
> > 
> > batman-adv will send your data from hostA to hostC via hostB when the TQ
> > value for the link "from hostA to hostC via hostB" is higher than the TQ
> > value for the link "hostA to hostC directly". This has nothing to do with
> > network coding and is a standard feature of batman-adv (this is actually
> > what it is about).
> > 
> > network coding can only (when lucky) try to combine some packets - but
> > this will only work when promiscuous mode is actually working and the
> > nodes can overhear packets. Otherwise it will (in theory - Martin please
> > correct me if I overlooked a safety mechanism) just create a lot of coded
> > packets which cannot be decoded anymore. This seems to be especially
> > problematic when some nodes are for example 2x2 MIMO devices and others
> > are 3x3. At least this would be a good way to let the 2x2 miss important
> > packets when the 3x3 devices talk between each other.
> > 
> > I would even guess that things like dynamic transmission power would make
> > overhearing packets also more problematic.
> > 
> >> but i have a question ? How many relay nodes can be supported at
> >> NetworkCoding ( mtu 1546 ) .
> > 
> > I am not sure what you are asking here. The implementation in batman-adv
> > can combine two packets into one. And this combining of these two packets
> > is done by exact one relay node. The decoding is done by the two receiving
> > nodes. What you can build with it is been shown in the documentation from
> > Martin. The network coding used here is therefore done by a relay node and
> > its neighbors. But there can be multiple relay nodes in the mesh doing
> > network coding at the same time.
> > 
> > 
> > I personally haven't used network coding with batman-adv. But since you've
> > created multiple new threads on the mailing list [1,2,3,4] (beside the
> > private mail *grml*) - here is at least a pseudo-answer.
> > 
> > Kind regards,
> > Sven
> > 
> > [1]
> > https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding#Drawback
> > s [2]
> > https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016586.ht
> > ml [3]
> > https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016587.ht
> > ml [4]
> > https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016588.ht
> > ml [5]
> > https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016592.ht
> > ml
> End of encapsulated message


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Re: [B.A.T.M.A.N.] i have a question ? How many relay nodes can be supported at NetworkCoding ( mtu 1546 ) .

[johnzeng]

Hello Dear Simon:

                               How will i do via batctl ? Do you mean 
that batman-adv can support it by default  at layer 2 ?

                               if Relay mode is based on Layer 2 ( route 
or Nat ) , it will be very complex and Infeasible at large wifi network

                               let's assume  the environment , node A  
can communicate with node B directly  via wifi and  node B can 
communicate with node C directly via wifi.

                               but node A can't communicate with node C 
directly via wifi ( master reason : Weak signal)  ,

                              Maybe Batman-adv can forward full 
Broadcast packet to next nodeC via nodeB , but if node A will build tcp 
connection between node A and nodeC ,

                              I can understand network coding , it will 
be same as proxy or Intermediator at Layer 2 ,


                             Your meaning :  Batman-adv can build 
Similar mechanism ( Intermediator )  via intermediator , it wil be  
relay based real application packet ( not relay based Broadcast packet)


                              Thanks

                              Best Regards

                              TIger
> On Tuesday, November 8, 2016 11:55:14 AM CET johnzeng via B.A.T.M.A.N wrote:
>> Hello Dear Sven and Martin:
>>
>>                                                Thanks for your advisement
>>
>>                                                I hope to aviod Excavation
>> of underground pipeline in the smart community or Park .
>>
>>                                                if Batman-adv can support
>> smart relay ( networking code ) at mesh network really , and it will be
>> very valuable for us .
> Hi Johnzeng,
>
> why are you insisting on using network coding? Batman-adv can do relay without
> network coding enabled, this is part of the basic mesh technology. Network
> Coding (or CATWOMAN) was research project/proof of concept implementation
> which isn't actively maintained right now. But from what I understood, your
> setups can be supported with "standard" batman-adv mesh.
>
> Thanks,
>      Simon
>
>>                                                i think one of  core
>> valuable point is  relay mode   and   Client roaming
>>
>>                                                i prepare to build more ap
>> evironment and test for the part  later
>>
>>
>>
>>
>> As market competition intensifies,
>>
>>                                                the gap between similar
>> productsis getting smaller and smaller,
>>
>>                                                likewise the evolution of
>> growing homogenization trends within the industry.
>>
>>
>>
>>                                                i hope we can find
>> valuable point for Blue Ocean each other .
>>
>>                                                if you have some different
>> point , and I would be happy to be the first and build win-win mode each
>> other .
>>
>>
>>                                                Best Regards
>>
>>                                                 Tiger
>>
>>> Hi,
>>>
>>>> When i compile the part , whether i need make
>>>> CONFIG_BATMAN_ADV_BATMAN_V=y at batman-adv-2016.2
>>> 2016.2 is "old". And BATMAN_V has nothing to do with network coding.
>>>
>>>> i read some detail about NetworkCoding , my understanding :
>>>>
>>>> every relay node will detects neighbors packet at promisc mode and
>>>> combine these packet into a single transmission ,
>>> I think Martin can help here. He also provided some documentation:
>>>
>>> * https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding
>>> *
>>> https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding-technica
>>> l *
>>> https://downloads.open-mesh.org/batman/papers/batman-adv_network_coding.p
>>> df *
>>> https://vbn.aau.dk/da/publications/catwoman(214ee21a-e786-495d-85c9-3efac
>>> 4718ead).html *
>>> https://downloads.open-mesh.org/batman/misc/wbmv4-network_coding.avi
>>>
>>> And it will not try to forward each packet is overheard. Instead it
>>> will try to find coding opportunities which it then uses to forward
>>> its own packets in less transmissions (by using packets which the
>>> other nodes should already know).
>>>
>>>> batctl nc 1
>>>> echo 1 > /sys/class/net/bat0/mesh/network_coding
>>>> ip link set dev wlan0 promisc on
>>>> ip link set dev wlan0 mtu 1546
>>> Your cards/drivers will most likely not even support promiscuous mode.
>>> Some of them require to have an monitor mode interface at the same time
>>> and
>>> some of them will simply not work.
>>>
>>> You can test it by simply checking what tcpdump is showing you on the
>>> underlying interface (wlan0). If it doesn't show you the packets between
>>> two other nodes then promiscuous mode is not working for you.
>>>
>>> The feature itself is not used very often (Martin, please correct me
>>> here).
>>> It is not enabled by default because it is not making things "better" all
>>> the time [1]. So it is also not tested as much as other components in
>>> batman-adv and you should think first if it is really useful for your
>>> scenario/HW. I knew at least from some Freifunk communities played around
>>> when it was enabled by default but had to revert when they experienced
>>> "non
>>> functional mesh links" (nothing more about it is known to me - sorry
>>> Martin).>
>>>> if i send a packet from host A to hostC via hostB, whether hostB will
>>>> open relay mode at layer2 .
>>> I completely failed to parse this.
>>>
>>> batman-adv will send your data from hostA to hostC via hostB when the TQ
>>> value for the link "from hostA to hostC via hostB" is higher than the TQ
>>> value for the link "hostA to hostC directly". This has nothing to do with
>>> network coding and is a standard feature of batman-adv (this is actually
>>> what it is about).
>>>
>>> network coding can only (when lucky) try to combine some packets - but
>>> this will only work when promiscuous mode is actually working and the
>>> nodes can overhear packets. Otherwise it will (in theory - Martin please
>>> correct me if I overlooked a safety mechanism) just create a lot of coded
>>> packets which cannot be decoded anymore. This seems to be especially
>>> problematic when some nodes are for example 2x2 MIMO devices and others
>>> are 3x3. At least this would be a good way to let the 2x2 miss important
>>> packets when the 3x3 devices talk between each other.
>>>
>>> I would even guess that things like dynamic transmission power would make
>>> overhearing packets also more problematic.
>>>
>>>> but i have a question ? How many relay nodes can be supported at
>>>> NetworkCoding ( mtu 1546 ) .
>>> I am not sure what you are asking here. The implementation in batman-adv
>>> can combine two packets into one. And this combining of these two packets
>>> is done by exact one relay node. The decoding is done by the two receiving
>>> nodes. What you can build with it is been shown in the documentation from
>>> Martin. The network coding used here is therefore done by a relay node and
>>> its neighbors. But there can be multiple relay nodes in the mesh doing
>>> network coding at the same time.
>>>
>>>
>>> I personally haven't used network coding with batman-adv. But since you've
>>> created multiple new threads on the mailing list [1,2,3,4] (beside the
>>> private mail *grml*) - here is at least a pseudo-answer.
>>>
>>> Kind regards,
>>> Sven
>>>
>>> [1]
>>> https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding#Drawback
>>> s [2]
>>> https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016586.ht
>>> ml [3]
>>> https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016587.ht
>>> ml [4]
>>> https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016588.ht
>>> ml [5]
>>> https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016592.ht
>>> ml
>> End of encapsulated message

Re: [B.A.T.M.A.N.] i have a question ? How many relay nodes can be supported at NetworkCoding ( mtu 1546 ) .

[johnzeng]

>
> Hello Dear Simon:

                                   Sorry , *there is a clerical error , 
i updated for it ( layer2 --> layer3 **second line)
*
>
>                               How will i do via batctl ? Do you mean 
> that batman-adv can support it by default  at layer 2 ?
>
>                               if Relay mode is based on Layer 3 ( 
> route or Nat ) , it will be very complex and Infeasible at large wifi 
> network
>
>                               let's assume  the environment , node A  
> can communicate with node B directly  via wifi and  node B can 
> communicate with node C directly via wifi.
>
>                               but node A can't communicate with node C 
> directly via wifi ( master reason : Weak signal)  ,
>
>                              Maybe Batman-adv can forward full 
> Broadcast packet to next nodeC via nodeB , but if node A will build 
> tcp connection between node A and nodeC ,
>
>                              I can understand network coding , it will 
> be same as proxy or Intermediator at Layer 2 ,
>
>
>                             Your meaning :  Batman-adv can build 
> Similar mechanism ( Intermediator )  via intermediator , it wil be  
> relay based real application packet ( not relay based Broadcast packet)
>
>
>                              Thanks
>
>                              Best Regards
>
>                              TIger
>> On Tuesday, November 8, 2016 11:55:14 AM CET johnzeng via B.A.T.M.A.N 
>> wrote:
>>> Hello Dear Sven and Martin:
>>>
>>>                                                Thanks for your 
>>> advisement
>>>
>>>                                                I hope to aviod 
>>> Excavation
>>> of underground pipeline in the smart community or Park .
>>>
>>>                                                if Batman-adv can 
>>> support
>>> smart relay ( networking code ) at mesh network really , and it will be
>>> very valuable for us .
>> Hi Johnzeng,
>>
>> why are you insisting on using network coding? Batman-adv can do 
>> relay without
>> network coding enabled, this is part of the basic mesh technology. 
>> Network
>> Coding (or CATWOMAN) was research project/proof of concept 
>> implementation
>> which isn't actively maintained right now. But from what I 
>> understood, your
>> setups can be supported with "standard" batman-adv mesh.
>>
>> Thanks,
>>      Simon
>>
>>> i think one of  core
>>> valuable point is  relay mode   and   Client roaming
>>>
>>>                                                i prepare to build 
>>> more ap
>>> evironment and test for the part  later
>>>
>>>
>>>
>>>
>>> As market competition intensifies,
>>>
>>>                                                the gap between similar
>>> productsis getting smaller and smaller,
>>>
>>>                                                likewise the 
>>> evolution of
>>> growing homogenization trends within the industry.
>>>
>>>
>>>
>>>                                                i hope we can find
>>> valuable point for Blue Ocean each other .
>>>
>>>                                                if you have some 
>>> different
>>> point , and I would be happy to be the first and build win-win mode 
>>> each
>>> other .
>>>
>>>
>>>                                                Best Regards
>>>
>>>                                                 Tiger
>>>
>>>> Hi,
>>>>
>>>>> When i compile the part , whether i need make
>>>>> CONFIG_BATMAN_ADV_BATMAN_V=y at batman-adv-2016.2
>>>> 2016.2 is "old". And BATMAN_V has nothing to do with network coding.
>>>>
>>>>> i read some detail about NetworkCoding , my understanding :
>>>>>
>>>>> every relay node will detects neighbors packet at promisc mode and
>>>>> combine these packet into a single transmission ,
>>>> I think Martin can help here. He also provided some documentation:
>>>>
>>>> * https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding
>>>> *
>>>> https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding-technica 
>>>>
>>>> l *
>>>> https://downloads.open-mesh.org/batman/papers/batman-adv_network_coding.p 
>>>>
>>>> df *
>>>> https://vbn.aau.dk/da/publications/catwoman(214ee21a-e786-495d-85c9-3efac 
>>>>
>>>> 4718ead).html *
>>>> https://downloads.open-mesh.org/batman/misc/wbmv4-network_coding.avi
>>>>
>>>> And it will not try to forward each packet is overheard. Instead it
>>>> will try to find coding opportunities which it then uses to forward
>>>> its own packets in less transmissions (by using packets which the
>>>> other nodes should already know).
>>>>
>>>>> batctl nc 1
>>>>> echo 1 > /sys/class/net/bat0/mesh/network_coding
>>>>> ip link set dev wlan0 promisc on
>>>>> ip link set dev wlan0 mtu 1546
>>>> Your cards/drivers will most likely not even support promiscuous mode.
>>>> Some of them require to have an monitor mode interface at the same 
>>>> time
>>>> and
>>>> some of them will simply not work.
>>>>
>>>> You can test it by simply checking what tcpdump is showing you on the
>>>> underlying interface (wlan0). If it doesn't show you the packets 
>>>> between
>>>> two other nodes then promiscuous mode is not working for you.
>>>>
>>>> The feature itself is not used very often (Martin, please correct me
>>>> here).
>>>> It is not enabled by default because it is not making things 
>>>> "better" all
>>>> the time [1]. So it is also not tested as much as other components in
>>>> batman-adv and you should think first if it is really useful for your
>>>> scenario/HW. I knew at least from some Freifunk communities played 
>>>> around
>>>> when it was enabled by default but had to revert when they experienced
>>>> "non
>>>> functional mesh links" (nothing more about it is known to me - sorry
>>>> Martin).>
>>>>> if i send a packet from host A to hostC via hostB, whether hostB will
>>>>> open relay mode at layer2 .
>>>> I completely failed to parse this.
>>>>
>>>> batman-adv will send your data from hostA to hostC via hostB when 
>>>> the TQ
>>>> value for the link "from hostA to hostC via hostB" is higher than 
>>>> the TQ
>>>> value for the link "hostA to hostC directly". This has nothing to 
>>>> do with
>>>> network coding and is a standard feature of batman-adv (this is 
>>>> actually
>>>> what it is about).
>>>>
>>>> network coding can only (when lucky) try to combine some packets - but
>>>> this will only work when promiscuous mode is actually working and the
>>>> nodes can overhear packets. Otherwise it will (in theory - Martin 
>>>> please
>>>> correct me if I overlooked a safety mechanism) just create a lot of 
>>>> coded
>>>> packets which cannot be decoded anymore. This seems to be especially
>>>> problematic when some nodes are for example 2x2 MIMO devices and 
>>>> others
>>>> are 3x3. At least this would be a good way to let the 2x2 miss 
>>>> important
>>>> packets when the 3x3 devices talk between each other.
>>>>
>>>> I would even guess that things like dynamic transmission power 
>>>> would make
>>>> overhearing packets also more problematic.
>>>>
>>>>> but i have a question ? How many relay nodes can be supported at
>>>>> NetworkCoding ( mtu 1546 ) .
>>>> I am not sure what you are asking here. The implementation in 
>>>> batman-adv
>>>> can combine two packets into one. And this combining of these two 
>>>> packets
>>>> is done by exact one relay node. The decoding is done by the two 
>>>> receiving
>>>> nodes. What you can build with it is been shown in the 
>>>> documentation from
>>>> Martin. The network coding used here is therefore done by a relay 
>>>> node and
>>>> its neighbors. But there can be multiple relay nodes in the mesh doing
>>>> network coding at the same time.
>>>>
>>>>
>>>> I personally haven't used network coding with batman-adv. But since 
>>>> you've
>>>> created multiple new threads on the mailing list [1,2,3,4] (beside the
>>>> private mail *grml*) - here is at least a pseudo-answer.
>>>>
>>>> Kind regards,
>>>> Sven
>>>>
>>>> [1]
>>>> https://www.open-mesh.org/projects/batman-adv/wiki/NetworkCoding#Drawback 
>>>>
>>>> s [2]
>>>> https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016586.ht 
>>>>
>>>> ml [3]
>>>> https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016587.ht 
>>>>
>>>> ml [4]
>>>> https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016588.ht 
>>>>
>>>> ml [5]
>>>> https://lists.open-mesh.org/pipermail/b.a.t.m.a.n/2016-November/016592.ht 
>>>>
>>>> ml
>>> End of encapsulated message
>

Re: [B.A.T.M.A.N.] i have a question ? How many relay nodes can be supported at NetworkCoding ( mtu 1546 ) .

[Linus Lüssing]

On Wed, Nov 09, 2016 at 04:50:45AM +0100, johnzeng via B.A.T.M.A.N wrote:
> Date: Wed, 09 Nov 2016 11:50:30 +0800
> From: johnzeng <johnzeng2013@yahoo.com>
> To: Simon Wunderlich <sw@simonwunderlich.de>
> CC: b.a.t.m.a.n@lists.open-mesh.org, Sven Eckelmann <sven@narfation.org>,
>  Martin Hundebøll <martin@hundeboll.net>
> Subject: Re: [B.A.T.M.A.N.] i have a question ? How many relay nodes can be
>  supported at NetworkCoding ( mtu 1546 ) .
> 
>                              I can understand network coding , it will be
> same as proxy or Intermediator at Layer 2 ,

Maybe there is a complete misunderstanding what "network coding"
is?

Maybe an easier expression would be "packet mixing" or "magic packet
mangling" [1].

Any code that does something with networking is usually *not*
"network coding" (at least in this context here).

Have a look at the links Sven has provided earlier.

> 
> 
>                             Your meaning :  Batman-adv can build Similar
> mechanism ( Intermediator )  via intermediator , it wil be  relay based real
> application packet ( not relay based Broadcast packet)

Just try it :-). Compile batman-adv *without network coding* with
your A-B-C scenario and see how it magically works, too :-).

Regards, Linus


[1]: Please no expert hit me :D. I know, ultimately, network coding would
replace packet based networks, if I remember Frank's talk
in Leipzig correctly

https://www.youtube.com/watch?v=yluj7e_rfVE

Re: [B.A.T.M.A.N.] i have a question ? How many relay nodes can be supported at NetworkCoding ( mtu 1546 ) .

[Linus Lüssing]

On Wed, Nov 09, 2016 at 04:56:52AM +0100, johnzeng via B.A.T.M.A.N wrote:
> Date: Wed, 09 Nov 2016 11:56:36 +0800
> From: johnzeng <johnzeng2013@yahoo.com>
> To: Simon Wunderlich <sw@simonwunderlich.de>
> CC: b.a.t.m.a.n@lists.open-mesh.org, Sven Eckelmann <sven@narfation.org>,
>  Martin Hundebøll <martin@hundeboll.net>
> Subject: Re: [B.A.T.M.A.N.] i have a question ? How many relay nodes can be
>  supported at NetworkCoding ( mtu 1546 ) .
> >                              if Relay mode is based on Layer 3 ( route or
> >Nat ) , it will be very complex and Infeasible at large wifi network

No, batman-adv has nothing to do with layer 3. For clients in batman-adv it
all looks like one, big switch.

It does that not by layer3 routing or layer3 NAT'ing, but by
encapsulating frames in its own headers.

Re: [B.A.T.M.A.N.] i have a question ? How many relay nodes can be supported at NetworkCoding ( mtu 1546 ) .

[johnzeng]

Hello Dear Linus:

                            Ok , i see , i will test it in according to 
your advisement .


                            Thanks , have a good day with you


                            Tiger



于 2016年11月09日 13:28, Linus Lüssing 写道:
> On Wed, Nov 09, 2016 at 04:50:45AM +0100, johnzeng via B.A.T.M.A.N wrote:
>> Date: Wed, 09 Nov 2016 11:50:30 +0800
>> From: johnzeng <johnzeng2013@yahoo.com>
>> To: Simon Wunderlich <sw@simonwunderlich.de>
>> CC: b.a.t.m.a.n@lists.open-mesh.org, Sven Eckelmann <sven@narfation.org>,
>>   Martin Hundebøll <martin@hundeboll.net>
>> Subject: Re: [B.A.T.M.A.N.] i have a question ? How many relay nodes can be
>>   supported at NetworkCoding ( mtu 1546 ) .
>>
>>                               I can understand network coding , it will be
>> same as proxy or Intermediator at Layer 2 ,
> Maybe there is a complete misunderstanding what "network coding"
> is?
>
> Maybe an easier expression would be "packet mixing" or "magic packet
> mangling" [1].
>
> Any code that does something with networking is usually *not*
> "network coding" (at least in this context here).
>
> Have a look at the links Sven has provided earlier.
>
>>
>>                              Your meaning :  Batman-adv can build Similar
>> mechanism ( Intermediator )  via intermediator , it wil be  relay based real
>> application packet ( not relay based Broadcast packet)
> Just try it :-). Compile batman-adv *without network coding* with
> your A-B-C scenario and see how it magically works, too :-).
>
> Regards, Linus
>
>
> [1]: Please no expert hit me :D. I know, ultimately, network coding would
> replace packet based networks, if I remember Frank's talk
> in Leipzig correctly
>
> https://www.youtube.com/watch?v=yluj7e_rfVE