WI-FI ROAMING 802.11r QUESTION

fbaffoni · Thu Aug 21, 2008 10:47 pm

Hi, people.

I have to make a new wireless wi-fi network in a city, this network should guarantee roaming for the clients. So, my idea is to use one AP and WDS distributing the signal all over the city. I know that mikrotik support this implementation of the 802.11 standar. But is Mikrotik capable to support 802.11r or 802.11f for mobile network?

If not, how could be the alternative metod to do this deployment?

Are the mikrotik people thinking about to add this standard on RouterOS future versions?

Thank you. I will wait for an answer.

sarpkaya · Fri Aug 22, 2008 12:19 am

I thought that problem nowadays, if you make ssid, mac addresses and channels same, client won't be able to understand that devices are different. So they'll connect whatever has high signal

fbaffoni · Fri Aug 22, 2008 3:51 am

I don´t think that you say work. Will be colisions at layer 2 level, and that will be a problem.

I know that 802.11r is the solution, but i don´t know if mikrotik support that.

Fri Aug 22, 2008 10:01 am

what sarpkaya says is true. that's what most hotels do, just make the same SSID. of course there will be a reconnection, I guess Uldis can explain more (?)

Fri Aug 22, 2008 10:15 am

we don't support 802.11r, but you can use RSTP in your WDS mesh networking where you have all the AP with the same SSID.

cuccio · Fri Aug 22, 2008 11:58 am

when client change the AP, lost any connection for some seconds. This is real problem for Voip, and for this reason 802.11r exist.

BR
C.

Fri Aug 22, 2008 11:59 am

when client change the AP, lost any connection for some seconds. This is real problem for Voip, and for this reason 802.11r exist.

BR
C.

I have talked to people who use Wifi Voip phones and their call doesn't interrupt if the system is properly configured.

fbaffoni · Fri Aug 22, 2008 3:40 pm

Normis

What do you mean with properly configured?

1)using RSTP?
2) using Layer2-Mesh?
3) using WDS-SLAVE?
4) Usint station-wds?

What do you think that "the properly configured" would be?

Thank you, i will wait for your answer

Fri Aug 22, 2008 4:06 pm

Here is documentations for Layer2 Mesh:
http://wiki.mikrotik.com/wiki/Layer-2_r ... h_networks

You can start configuring WDS with RSTP. If you are more advanced you can configure also Layer 2 Mesh.
Usually you loose only few frames when you connect to other AP, and you will not notice that on the VOIP connection.

fbaffoni · Fri Aug 22, 2008 4:25 pm

Uldis

You say that i will loose some frames that will not affect the VoIP communications ustin RSTP or using L2-Mesh?

Thank you for your response

Fri Aug 22, 2008 4:29 pm

This could effect both of them, usually one or two frames could be lost, so you would not notice that. You can ask on the forum for client who are using such systems on mesh networks.

fbaffoni · Fri Aug 22, 2008 4:46 pm

Ok Uldis, thank you, i will test it.

Thank for your time men.

sarpkaya · Fri Aug 22, 2008 11:03 pm

what sarpkaya says is true. that's what most hotels do, just make the same SSID. of course there will be a reconnection, I guess Uldis can explain more (?)

Hotels are doing only ssid same. But my thought is different if ssids are same but mac addresses are different, there should be a connection problem when you're mobile(in car, in bus, in bike etc...) and connecting wi-fi that will make problem because that connection will be lost in 1 minute and try to search for 10 sc so user will have %80 connectivity. But If mac address will be same, that will make no problem and there is no connection lost.

fbaffoni · Fri Aug 22, 2008 11:16 pm

Sparkaya

I understund your point, but 2 AP, connected in the same LAN, with the same MAC address, will cause colissions at layer 2 level. It´s the same thing if you configure 2 PC with the same IP Address. That is the problem becouse you can't use the same MAC address for the AP.

sarpkaya · Sat Aug 23, 2008 12:28 am

Sparkaya

I understund your point, but 2 AP, connected in the same LAN, with the same MAC address, will cause colissions at layer 2 level. It´s the same thing if you configure 2 PC with the same IP Address. That is the problem becouse you can't use the same MAC address for the AP.

Mmm, that's strange.
If you do communication with another device, I mean do your backhaul with another device, so mac addresses will be different in lan side. It will show different mac address(backhaul's mac address)

If you have better solution tell us, we'll learn.

fbaffoni · Sat Aug 23, 2008 4:49 am

Yes, through that way will work, becouse the Wlan Mac, will be masquered with the LAN Mac.

But, I will not use the lan side, becouse I needing a complete wireless solution, just one core router will be connected through the lan.

This is the idea

Internet(ethx)-----AP1(core router) - - - - (wireless) - - - - AP2(WDS Bridged) - - - Clients
................................................... - - - - (wireless) - - - - AP3(WDS bridged) - - - Clients

Using WDS the AP2 and AP3 will be a mirror of the AP1, so all the network will be bridged, so all MAC address will be in the network, including the AP2 and AP3 wireless MAC address.

That is why i can´t do that... :S

I will test with RSTP and L2-Mesh, and I will post my results.

Thank you for your time buddy, I really appreciate.

ottife · Fri Aug 29, 2008 7:00 pm

I used layer2 mesh plus WDS with ROS,it works and the ping will be lost 2~15 pakcets when switch over from one AP to another AP,after I changed the hwmp-prep-lifetime to 1s.And I think if there are many APs inside the mesh domain,the mesh signaling traffic will be high heavy.
And I also tested the mobility effect with Cisco 802.11r ready AP,none ping packet is lost.

cuccio · Fri Aug 29, 2008 7:08 pm

Yes, confirm, 802.11r dont loose packets.

Bye
C.

XaTriX · Thu Feb 20, 2014 5:58 pm

bump!

5 years later : same question. Is, now, 802.11r supported ? (here 951g-2hnd)

XaT

XaTriX · Fri Feb 21, 2014 12:26 pm

syadnom · Fri Jun 27, 2014 5:30 am

still a valid questions.

Also, 'properly configured' and requiring WDS and a lot of tweaking is not 'properly configured', it's 'tweaked'.
802.11r support is a real need for VoIP phones and building out a tweaked wifi network when the effort and expense should have been spent on ideal AP placement, count, and power levels. If the site is properly surveyed and built, 802.11r is the absolute obvious and most efficient and least maintenance solution. Cisco, Aruba, Meraki, others already support this and there are many devices on the market.

My customers are moving to VoIP rapidly, it's my fastest growing product, and right now I'm pairing up DECT handsets because of the lack of 802.11r in mikrotik and ubiquiti gear. DECT is fine, but SIP VoIP handsets would be a welcome improvement.

mcdebugger · Sun Aug 16, 2015 12:19 am

Yeah, we're still waiting for this..

efaden · Sun Aug 16, 2015 1:59 pm

Would be nice.

sup5 · Mon Aug 17, 2015 12:32 pm

If you really need seamless Wifi Roaming you need to choose another vendor: Meru Networks.
They use the "single channel architecture", which makes all access points appear as a single one to WiFi clients.
Roaming will happen in lesser than 50ms.

tolstii · Sun Sep 06, 2015 11:07 pm

guys on mikrotik can be "seamless roaming", if properly set up! We have implemented and are implementing many projects where it is necessary to cover large areas with a high density, and it is essential that the transition to the connection is not torn (eg VOIP), so that's all you can do and it works! If you want to attach a video.

Just tomorrow we go to the object in which will be install 25 AP in a large warehouse for data collection terminals

sorry for my English

Lupin · Sat Sep 19, 2015 6:32 pm

+1 for 802.11r support

Hammer · Sat Nov 28, 2015 5:00 pm

guys on mikrotik can be "seamless roaming", if properly set up!

and how to set up properly?

Sat Nov 28, 2015 6:32 pm

It's impossible wit mikrotik. Very close solution is capsman but even it is almost seamless you can see the delay in traffic or even some drop can occur when roaming. But normally it is acceptable.

barkas · Sat Nov 28, 2015 7:03 pm

Devices have a tendency to hang on to weak signals so that doesn't work too well usually.

802.11r please.

Sat Nov 28, 2015 7:23 pm

there is no magic solution to roaming problems

the best solution is to make a very good design, very good pre implementation site survey, very good post implementation site survey and tunning.

with that the time taken for roaming using wpa2-psk and aes is inferior to a second, specially when clients driver of wifi chipset collaborates

you have to take in mind roaming its very client dependent specially when you dont have control of your clients (smartphones of many brands and version of OS, tablets, laptops with many and different wifi chipset vendors and different drivers versions).

mikrotik + good implementation + good clients = spectacular wifi

soonwai · Fri Feb 24, 2017 3:57 am

802.11r/k/v imlementation would be good. There are already tens of millions of client devices which supports it. It's not seamless but will be better than what we have now.

francogp · Thu Jul 15, 2021 12:44 am

Any news on this topic? (13 years later bump)

dave864 · Fri Jul 23, 2021 8:11 pm

It has been decided that old equipment will not get r k v and that new equipment, not yet released will get these features. This is based on old stuff using a custom wi-fi code. MT will not back port because the firmware flash storage in those devices is typically too small at about 16MB I believe.

I'd add, there is a very small bit of free space and so they may be able to pick one of the three features only but I guess the risk is that there would be no space for general software updates. The flash is just too small. An over the air update system could be implemented but would cost to develop and may not alleviate all problems as then you would transfer the issue to the limited ram. Which quite frankly, the best option is to forget about these legacy devices - just give them bug fixes, security updates and instead concentrate on some new hardware with large flash and ram capacities.

I'm salty about this but at the same time agree with the approach. I would really hope that the new hardware comes with plenty of space!

ivicask · Sun Jul 25, 2021 9:17 pm

Whats wrong with capsman roaming, works with any Mt hardware, and works wonderful.

whatever · Mon Jul 26, 2021 10:00 am

There is no "capsman roaming". Any client roaming is unrelated to capsman.

pe1chl · Mon Jul 26, 2021 12:15 pm

It has been decided that old equipment will not get r k v and that new equipment, not yet released will get these features. This is based on old stuff using a custom wi-fi code. MT will not back port because the firmware flash storage in those devices is typically too small at about 16MB I believe.

I'm salty about this but at the same time agree with the approach. I would really hope that the new hardware comes with plenty of space!

Ironically, MikroTik devices originally had 64 or 128 MB flash even on the low-end devices, but MikroTik did special development to be able to produce new devices with only 16MB flash. A special trick to download firmware updates in a RAMdisk and then install them from there.
Also, with this change the capability to have 2 partitions with two different RouterOS versions (and auto failover when one fails to boot) was lost.

At the time that happened, lots of forum users were questioning that move. It was foreseen that they would run out of space for future firmware expansion.
But MikroTik people on the forum always replied that this was not the case, that there was no problem with that, and there was enough space.

So it is funny that now they would decide not to have basic functionality of a WiFi access point in "old" equipment (I presume that would be the "new" equipment discussed above, because really old equipment has enough space), "due to space restrictions".
At the same time, the modularity of RouterOS (to have a smallish "base" package and additional separate packages for things like the wireless driver) is also being phased out, so it isn't possible to specialize the devices either. An access point that is part of a roaming system would normally not require modules like routing, dhcp, ppp, probably not even advanced-tools. So by omitting those, a larger wireless package could be accommodated. However, in version 7 there are no separate packages for such common purposes anymore, only some niche packages for things like monitoring a UPS.

It has always been clear that 16MB is very little space. But it was decided that it was enough, and that was confirmed after questions were raised about it.
I fully expect that version 7 will not be released for 16MB flash systems in the end either, because it is already expanding into the region where you cannot install it via update (and do in-place updates) anymore.

mkx · Mon Jul 26, 2021 1:19 pm

So it is funny that now they would decide not to have basic functionality of a WiFi access point in "old" equipment (I presume that would be the "new" equipment discussed above, because really old equipment has enough space), "due to space restrictions".

It's not that "basic functionality" is going away, wireless models will keep their current wireless functionality even with ROS v7. It's new functionality (not available in v6) that will not be available on all devices with capable hardware. E.g. most (if not all) ac chipsets used in mikrotik wifi devices should be capable of wave2 functionality. Which requires plenty of flash storage and even more RAM. And that's not functionality provided by hardware in the old devices with lots of storage (BTW, older devices did not easily come with 256 RAM, required by new wave2 wireless drivers). So there are relatively few devices which could benefit of new wireless drivers but won't be able to use it due to tiny storage space (most notably hAP ac2 and cAP ac).

ivicask · Mon Jul 26, 2021 1:33 pm

There is no "capsman roaming". Any client roaming is unrelated to capsman.

So how im going thru 4 floors of school with my phone running ping to google servers, and drop zero pings, while switching between 15 different mikrotik aps?
Isnt this an example of what you want to achieve?

mkx · Mon Jul 26, 2021 2:20 pm

Wireless clients scan for other APs from time to time (probably more frequently when signal strength of currently used AP drops below some threshold). If client finds AP with same SSID and with better signal strength, it will change to the new one. Device will assume same SSID means same LAN, so it won't loose time performing DHCP lease procedure. And that happens really quickly so simple pinging won't notice it. Real-time streaming services, OTOH, will notice the change, quite possibly it will loose some packets which (with RTSP stremaing) won't be retransmitted.

CAPsMAN roaming performs just the same way I described above. CAPsMAN is about provisioning radios and (if local-forwarding=no) about centralized bridging/routing (which only shows benefits when network between CAP and CAPsMAN is not L2 transparent network).

pe1chl · Mon Jul 26, 2021 4:30 pm

It's not that "basic functionality" is going away, wireless models will keep their current wireless functionality even with ROS v7.

Well, of course what is to be called "basic functionality" changes over the course of time, and so do the expectations of customers.
When you buy a WiFi AP with central management features (CAPsMAN) in 2019 or 2020, you consider 802.11r/k/v as "basic functionality". In 2008 (start of this topic) you would probably call it "advanced functionality" and ask if it could be added.
Of course MikroTik by now is so much behind on "basic functionality" that most people no longer consider it when doing company WiFi AP deployments.
That is a market they will have to fight back into. Which is mostly due to their own fault. But that has been discussed often enough, so no need to further discuss it in this topic.

anuser · Mon Jul 26, 2021 10:26 pm

256 RAM, required by new wave2 wireless driversb]2[/b] and cAP ac).

MikroTik cap AC uses IPQ4018 chipset, 128 MB RAM, 16 MB ROM. MikroTik tells us, that wifiwave2 drivers (with MU-MIMO support) need more RAM and ROM.
AFLA AL120C-AC uses IPQ4018 chipset, 128 MR RAM, 16 MB ROM and supports MU-MIMO.
=> MikroTik could provide a wifiwave2 package with the IPQ4018 drivers only for cAP ac and hAP ac2 without any problem which would run on those access points, aswell. The question is why doesn´t MikroTik want to do it?

pe1chl · Mon Jul 26, 2021 11:34 pm

Likely they do not want to make another "SwOS" ("APOS"?) that runs bare accesspoint functionality to make space (i.e. not having RouterOS) as they well know that this means constant requests for "but could you at least add THIS..." and also they cannot compete in that market anyway.
It could only serve them when it at least can be managed using CAPsMAN on a MikroTik router in the same network, and as it is now that would likely require a CAPsMAN redesign or a lot of code in the AP, for which there is no room.

Who is online