What is the maximum number of nodes supported by Mesh ?

[sritam2]

Dear All,

I have been working with 802.11s Mesh following the instructions at the HOWTO page. I am successful in forming the Mesh network using Laptops with Ubuntu 14.04 installed. I have the following doubts:

1. What is the maximum number of nodes(laptops in my case) that the Mesh network can support ? In other words what is the scalability in terms of size of the Mesh network ?

2. How to configure the maximum number of peer links that a node can have ? After forming links with a certain number of peers, the node will not allow any more joining. Is this possible/configurable ?

Please help me in answering these questions. Looking forward to your help.

Thanks and Regards,
Sritam Paltasingh.

[chunyeow]

Look at mesh_max_peer_links which is currently limited or restricted to 32. Theoretically it can be scale as large as you want. Some of the nodes may route 2, 3 hops... away. But with additional hop away from your destination, the throughput will be reduce by half.

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On Mon, Jul 3, 2017 at 4:22 PM, sritam2 ***@***.***> wrote: Dear All, I have been working with 802.11s Mesh following the instructions at the HOWTO page. I am successful in forming the Mesh network using Laptops with Ubuntu 14.04 installed. I have the following doubts: 1. What is the maximum number of nodes(laptops in my case) that the Mesh network can support ? In other words what is the scalability in terms of size of the Mesh network ? 2. How to configure the maximum number of peer links that a node can have ? After forming links with a certain number of peers, the node will not allow any more joining. Is this possible/configurable ? Please help me in answering these questions. Looking forward to your help. Thanks and Regards, Sritam Paltasingh. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#62>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABBewiiqC2YBP6KaqW9FGwF7BCRRQJncks5sKKSwgaJpZM4OL-Ms> .

[jcard0na]

Hi Chun-Yeow, Not really by half, throughput degrades by one over the number of hops. And that is if all nodes can interfere with one another. See the Figure 6 in the article linked below: http://www.academia.edu/21587927/IEEE_802.11s_The_WLAN_Mesh_Standard Cheers, Javier

On Tue, Jul 4, 2017 at 7:46 AM Chun-Yeow ***@***.***> wrote: Look at mesh_max_peer_links which is currently limited or restricted to 32. Theoretically it can be scale as large as you want. Some of the nodes may route 2, 3 hops... away. But with additional hop away from your destination, the throughput will be reduce by half. On Mon, Jul 3, 2017 at 4:22 PM, sritam2 ***@***.***> wrote: > Dear All, > > I have been working with 802.11s Mesh following the instructions at the > HOWTO page. I am successful in forming the Mesh network using Laptops with > Ubuntu 14.04 installed. I have the following doubts: > > 1. > > What is the maximum number of nodes(laptops in my case) that the Mesh > network can support ? In other words what is the scalability in terms of > size of the Mesh network ? > 2. > > How to configure the maximum number of peer links that a node can have > ? After forming links with a certain number of peers, the node will not > allow any more joining. Is this possible/configurable ? > > Please help me in answering these questions. Looking forward to your help. > > Thanks and Regards, > Sritam Paltasingh. > > — > You are receiving this because you are subscribed to this thread. > Reply to this email directly, view it on GitHub > <#62>, or mute the thread > < https://github.com/notifications/unsubscribe-auth/ABBewiiqC2YBP6KaqW9FGwF7BCRRQJncks5sKKSwgaJpZM4OL-Ms > > . > — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#62 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AApRVXc-eLkrkwpw7Fr0MzoWxwDRPzmaks5sKlBWgaJpZM4OL-Ms> .

-- http://okio.io

[sritam2]

Dear All,

Thank you for the valuable information. I went through the links and read the articles.

I am trying to form the mesh network using SAE authentication in a very busy channel (channel 6 - 2437 Mhz). I am keeping the channel busy with data traffic by downloading torrent files from internet via router set at channel 6. But still the authentication time (calculated from time stamps of wpa_supplicant) is not affected even though the channel is very busy. It takes the same time compared to the authentication time when the channel was free (near by access points, routers, other devices were all off).

How is this possible?? Even if the channel is heavily loaded with network traffic, the authentication time required for new node to become part of MBSS is still unaffected ?? Any reason for that?
Is it that authentication traffic is given more priority than normal data traffic ??

Please help me in clearing this doubt of mine.

Thanks and Regards,
Sritam.

[chunyeow]

Hi, Javier Yup, agreed based on the measurement results from the article. By the way, there are features on 802.11ac like MU-MIMO and upcoming 802.11ax that will allow better mesh throughput.

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--- Chun-Yeow On Wed, Jul 5, 2017 at 1:42 AM, Javier Cardona <notifications@github.com> wrote:

Hi Chun-Yeow, Not really by half, throughput degrades by one over the number of hops. And that is if all nodes can interfere with one another. See the Figure 6 in the article linked below: http://www.academia.edu/21587927/IEEE_802.11s_The_WLAN_Mesh_Standard Cheers, Javier On Tue, Jul 4, 2017 at 7:46 AM Chun-Yeow ***@***.***> wrote: > Look at mesh_max_peer_links which is currently limited or restricted to 32. > > Theoretically it can be scale as large as you want. Some of the nodes may > route 2, 3 hops... away. But with additional hop away from your > destination, the throughput will be reduce by half. > > On Mon, Jul 3, 2017 at 4:22 PM, sritam2 ***@***.***> wrote: > > > Dear All, > > > > I have been working with 802.11s Mesh following the instructions at the > > HOWTO page. I am successful in forming the Mesh network using Laptops > with > > Ubuntu 14.04 installed. I have the following doubts: > > > > 1. > > > > What is the maximum number of nodes(laptops in my case) that the Mesh > > network can support ? In other words what is the scalability in terms of > > size of the Mesh network ? > > 2. > > > > How to configure the maximum number of peer links that a node can have > > ? After forming links with a certain number of peers, the node will not > > allow any more joining. Is this possible/configurable ? > > > > Please help me in answering these questions. Looking forward to your > help. > > > > Thanks and Regards, > > Sritam Paltasingh. > > > > — > > You are receiving this because you are subscribed to this thread. > > Reply to this email directly, view it on GitHub > > <#62>, or mute the thread > > < > https://github.com/notifications/unsubscribe-auth/ ABBewiiqC2YBP6KaqW9FGwF7BCRRQJncks5sKKSwgaJpZM4OL-Ms > > > > . > > > > — > You are receiving this because you are subscribed to this thread. > Reply to this email directly, view it on GitHub > <#62 (comment)>, or mute > the thread > <https://github.com/notifications/unsubscribe-auth/AApRVXc- eLkrkwpw7Fr0MzoWxwDRPzmaks5sKlBWgaJpZM4OL-Ms> > . > -- http://okio.io — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#62 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABBewlSPeJZorPoNSkeMqRi-esH5_Fa6ks5sKnl3gaJpZM4OL-Ms> .

[sritam2]

Hi Chun-Yeow/Javier,

The authentication time measured (SAE is used) is unaffected even if the channel (channel 6 is used) is very busy. This is simulated by downloading torrent files from internet with router set at channel 6. The router is placed very close to the testbed consisting of Mesh node laptops.

But still the authentication time is 1.04 seconds. It is the same when router is off and only Mesh traffic is in the air.

Any reason for such a behavior??

Please help me.

Thanks and Regards,
Sritam Paltasingh.

[chunyeow]

Try to understanding the mesh peering and mesh authentication procedures by looking into the standard. Currently, the implementation is based on the passive scanning or detecting beacon frame (usually sent with lowest Tx rate) to trigger the mesh authentication and peering. Else you need to dig into the code to understand more.

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--- Chun-Yeow

On Wed, Jul 5, 2017 at 11:47 PM, sritam2 ***@***.***> wrote: Hi Chun-Yeow/Javier, The authentication time measured (SAE is used) is unaffected even if the channel (channel 6 is used) is very busy. This is simulated by downloading torrent files from internet with router set at channel 6. The router is placed very close to the testbed consisting of Mesh node laptops. But still the authentication time is 1.04 seconds. It is the same when router is off and only Mesh traffic is in the air. Any reason for such a behavior?? Please help me. Thanks and Regards, Sritam Paltasingh. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#62 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABBewg05QqGjpURYKD-wChrP2VjiK6LYks5sK6_3gaJpZM4OL-Ms> .

[sritam2]

Hi Chun-Yeow,

Thank you so much for your valuable advise. I will go through the mesh peering and mesh authentication procedures.
Should I look into IEEE 802.11-2012 specification released by IEEE in 2012 for understanding the mesh peering and authentication ?? If you know any other document which I should read for understanding mesh peering and authentication, then please refer me the name of the document.

Does the open80211s stack (which is part of linux kernel) implement passive scanning to trigger the mesh authentication and peering ??

Thanks and Regards,
Sritam Paltasingh.

[bcopeland]

On Wed, Jul 05, 2017 at 09:06:57AM -0700, sritam2 wrote: Hi Chun-Yeow, Thank you so much for your valuable advise. I will go through the mesh peering and mesh authentication procedures. Should I look into IEEE 802.11-2012 specification released by IEEE in 2012 for understanding the mesh peering and authentication ?? If you know any other document which I should read for understanding mesh peering and authentication, then please refer me the name of the document.

Yes, please read sections 11.5.1.3.4 and 13.3 from 802.11-2012. Hint: SAE exchange is done with authentication management frames -- which AC do those use? See section 9.2.

Does the open80211s stack (which is part of linux kernel) implement passive scanning to trigger the mesh authentication and peering ??

For secure mesh, wpa_supplicant drives the authentication and peering process with some help from the kernel (namely, receiving peer notifications when beacons arrive). If the network device is configured to receive matching beacons, you'll get them passively.

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-- Bob Copeland %% https://bobcopeland.com/

[sritam2]

Hi Bob,

Thank you for the valuable information. I will go through the sections.
I have the following questions:

1. For secure Mesh, is the authentication and peering process, specified by IEEE 802.11-2012 for Mesh networks, completely implemented and driven by wpa_supplicant ?? In order words, does wpa_supplicant implement the SAE specification described in IEEE 802.11-2012 for forming secured Mesh ?

[sritam2]

Dear All,

Is it possible to have pairwise password between mesh stations in an MBSS. Presently, I am using the same shared password among all nodes of the Mesh configured in wpa_supplicant.conf

Is it possible to define pairwise password for each secured link that a Mesh station forms. So, if a station has links to 3 different stations which are at one-hop distance away from this station, then is it possible that the Mesh station authenticates the 3 different stations (one-hop away) using 3 different password pairs (one for each station).

According to IEEE 802.11-2012, it should be possible. If yes, then how to implement it using wpa_supplicant ??
should there be multiple entries for "psk" field in wpa_supplicant.conf file ??

Thanks and Regards,
Sritam.