[FAQ] Using two routers together/ Extending Wi-Fi

Davemazo

Active Member
Many thanks both. I don't have any problems at the moment thanks to the excellent advice here so hopefully I'll be able to add another spare router/AP without any problems, fingers crossed.
 

mickevh

Distinguished Member
When we go above three cells (AP/"routers") life gets interesting in the 2.4GHz waveband. (Same deal in 5GHz, it's just there's more channels available to start with; upwards of 25 in the EU (with some caveats) last time I checked.

The "game" then is to try and arrange for any cells on the same channel to be a far apart (physically) as possible (or with substantial or radio opaque structures between them.)

It can be a challenge because the coverage footprint of a Wi-Fi cell is not just the extent of transmissions from the AP/router, but the union (in the Venn diagram sense) of the AP/router and all it's Associated clients (which each have their over transmission footprint.) It can be quite big if clients are out at the edges of the AP/router footprint.

Another dodge we sometimes use in big deployments is to use a [1,5,9,13] channel plan. Technically that means each channel is slightly overlapping it's neighbour in terms of the frequencies used, but sometimes it works well enough and gives you an extra channel to play with.

This article from Ekahau (a respected seller of Wi-Fi surrvey tools) has some nice graphics illustrating how to do channel planning, (though bear in mind the author is in the USA and available channels may differ in other territories.)

 
Last edited:

Davemazo

Active Member
Thanks Mick, much appreciated. Most of it makes sense but I must admit some of it is a bit over my head.

At the moment my system works fine, although your link does (I think) explain why my wife with her ipad moans that she can't get on the internet, while my android tablet or phone is working fine.

I'm not quite ready to set up that garage yet but armed with the information here I don't predict any problems.

One thing I do want to sort out is on all my access points is the 5ghz network. I'm sure my routers are 5ghz capable but are not showing it. I'm pretty sure my main BT router switches between 5ghz and 2.4ghz automatically at the moment but I can sort that out when I can get round to it.

Thanks again for your help.
 

mickevh

Distinguished Member
Most routers/AP's that offer 5GHz do so as well as 2.4GHz rather than one or the other. It's kind of like having two AP's in the same box, one serves 2.4GHz, one serves 5GHz. It's often styled as "dual band." (Often inside the boxes, there's two completely separate sets of antenna, amplifiers, etc. for each waveband, though these days a lot if it is probably integrated into a single "chip.")

If you set the SSID's the same in both wavebands (you don't have to) then the decision as to which waveband to use is made by the client devices, not the AP/Routers. When and whether to switch between them is also a decision made by the client devices, not the AP/Routers.

It just like the mechanism that's used to decide when to roam between physical AP's/Routers, it's all down to the client devices to decide. Some kit has a few "tricks" to try and encourage clients to one or other waveband, but they tend to be implemented less often in SOHO kit.

If you make the SSID's in each waveband different, then the clients will never roam between them automatically, just like physical AP's with different SSID's, you have to flip them manually.

There's no real "right" or "wrong" way to do this, both approaches have their virtues and vices. Most people prefer the simplicity of use of automatic roaming and waveband selection (SSID's all the same) but some people prefer the level of control differing SSID's avails in that you can be certain which AP/waveband you are talking to and/or might want to use it as a way to distribute clients between AP's/wavebands to optimise the performance.

Of course, in order to be able to "see" both wavebands, clients need to be "dual band" themselves and not all are. In the early days of Wi-Fi there was a lot of "2.4GHz only" kit and there's still some even today. So never "just assume" - check the specs. of your equipment.

Some clients have settings that will let you favour or even outright mandate a particular waveband and some will automatically go for 5GHz if they can as that's where the faster speeds are. If any particular devcie offers no controls, then we are in the gift of the device designer as to how they decided to favour any particular waveband or protocol, if they did so at all.
 
Last edited:

oneman

Well-known Member
Just to complicate matter, there is a new standard available, WiFi 6 which surprise, surprise runs on 6GHz. Faster than 5GHz but shorter range. It does come with a couple of features to make better use of the bandwidth. Look for AX in the model name or features.

At the moment not may ISP supplied routers support it but there are plenty of 3rd party ones that do and mid range and flagship phones from the last couple of years probably do as well and a growing number of laptops. Main thing I find is that if you can get your high usage devices (mainly ones that stream high def video) onto 5Ghz or 6Ghz then it frees up capacity on 2.4 GHz.
 

psychopomp1

Member
Just to complicate matter, there is a new standard available, WiFi 6 which surprise, surprise runs on 6GHz.
I suspect you meant Wifi-6E, as Wifi-6 has been out for a couple of years or so and can run on the 5ghz band.
 

redmike5

Novice Member
Hi there,

I am new to this game and read the thread with very high interest. There is a lot information here and I used the practical guide on page 1 and set up a home network with two routers.

The primary aim being the extension of the wifi coverage to the back of the house and to allow for seamless use of wifi, i.e. the same SSID, when carying mobiles around the house.

The primary router connecting to the ISP is Virgin Media Superhub 3. The only setting I modified is the DHCP range which I curbed down to 192.168.0.10 to 192.168.0.100. I didn't touch any other settings and the wifi configuration is as default.
The IP of the router is the default 192.168.0.1.

This router connects via cat 5 cable to an Archer VR600 router at the back of the house. The connection is LAN to LAN.

The secondary router IP address is set to 192.168.0.101 and the DHCP server is disabled. The wifi SSID and password are the same as in SH3. Security is the same (WPA2-PSK). I set the channels to 11 and 100 for 2.4 and 5G, respectively. On the primary I left the Enable Channel Optimization on, but it seems to be using channels 6 and 44.

The extended network seems to work great in a static situation. I.e. the kit which is stationary doesn't seem to drop connection. But not so the mobile kit. For example when we want to watch clip on YT and move from the range of one router to the range of the other the connection drops and takes long time to re-establish. The mobile would usually say something along Can't get IP address etc, depending on the actual mobile.

Interestingly the connection only drops when moving from the range of the primary to the secondary router. In the opposite direction it all works seamlessly.

I have tried changing settings on the secondary router, but to no avail. Considering that the problem was with obtaining IP address by the mobile kit, I set a reserved MAC/IP list in the SH3 to include the mobile phones. Again, no improvement.

Am I missing anything?

I am ready to give up after spending on this most evenings for the past week.
But if any one has any suggestions, I am more than happy to battle this for few more days.

Any help will be much apreciated.
 
Last edited:

tom 2000

Distinguished Member
I don’t know if seamless roaming is achievable. For that reason I give each access point a different SSID and select the one that should work when my phone holds onto a useless one which it does do regularly.
 

mickevh

Distinguished Member
"Seamless roaming" is something of an oxymoron - generally it just means it requires no user interaction.

Much of the process is vested in the client devices - it is they that decide if/when to roam and control the interactions with the AP's (routers) to effect the swap. Some are simply just better at than others and there's nothing much we an do about.

For example, a lot of clients (needlessly) request a new IP address when the roam and that's a process that isn't instant. If the IP address changes as a result, it can upset a lot of applications.

Sometimes things get a bit more "interesting" if the roam requires a change of protocols or security paradigms, so you can help it by getting everything except the radio channels as similar as possible. For example, if all your client devices are N and/or AC capable, you could try disabling support for the older A/B/G protocols, but it's a bit of a forlorn hope.

Of course, a heterogeneous equipment mix can also cause issues - on big sites we'd use a manage fleet of AP's that are all more or less the same and managed from a single platform.

Channel 100 is one of the "DFS" channels (which have some special handling in the presence of RADAR) you could maybe try experimenting with one of the other non-DFS channels (48 or lower.)

It may be that you are suffering interference from a neighbour. Again, not much you can do about that, but you could take a survey and see if you can devise a channel plan that either avoids them completely or avails the best "signal margin" (difference between you and them if on the same channel.) Trouble is, a lot of people leave their kit set up for auto-everything out of the box, so you might find a carefully designed neighbour avoiding channel plan falls to pieces weeks/months later if the neighbours' kit re-tunes for some reason.

@redmike5 - your settings look fine, I doubt there's anything you could change on your routers to make it work better. It is what it is.
 
Last edited:

redmike5

Novice Member
I don’t know if seamless roaming is achievable. For that reason I give each access point a different SSID and select the one that should work when my phone holds onto a useless one which it does do regularly.
Thanks Tom. We have an old house with thick solid walls and the current router is not in the best location. However, all the structural cabling is such that moving the main router is not really an option. Now the youngsters in the house often stream music from YT via their mobiles when they move about their chores in the house. And we have a few spots at the back of the house, where the wifi coverage is patchy. The best option would be a mesh system, the cost of the kit and work required to hide the hardware and extra power points is not worth it for the little gain it would offer. So having been given a spare router, I thought I would give it a go. As I already written the results are not exactly what I expected.

With regards how seamless the switching between nodes is, it doesn't have be to be completely seamless. Music streaming is buffered, so a few seconds drop in connection is not a problem. This is the case when going from secondary router coverege to primary. The music never stops. I didn't try it with another app, but just looking at the signal strength indicator teh wifi never drops completely.

But the annoying thing is that the other way round from primary to secondary router I need to wait for few minutes, before the wifi reconnects. When I forget the network and join again, then is starts without delay. So I was wondering whether I missed some setting in one of the routers and hence my post.

So thanks for your response. I have tried a few more things night including Mick's suggestions, but I think it is time to move to plan B. I am going to use the SH3 as a modem only and relocate the VR600 to where the SH3 is and use it to provide wifi over the entire house. Reading here and elsewhere that SH3 wifi coverage is not great, I hope that the other router will give me few extra meters of range and this is really all I need, 2 or 3 more meters of decent coverage towards the back of the house.
 

redmike5

Novice Member
"Seamless roaming" is something of an oxymoron - generally it just means it requires no user interaction.

Much of the process is vested in the client devices - it is they that decide if/when to roam and control the interactions with the AP's (routers) to effect the swap. Some are simply just better at than others and there's nothing much we an do about.

For example, a lot of clients (needlessly) request a new IP address when the roam and that's a process that isn't instant. If the IP address changes as a result, it can upset a lot of applications.

Sometimes things get a bit more "interesting" if the roam requires a change of protocols or security paradigms, so you can help it by getting everything except the radio channels as similar as possible. For example, if all your client devices are N and/or AC capable, you could try disabling support for the older A/B/G protocols, but it's a bit of a forlorn hope.

Of course, a heterogeneous equipment mix can also cause issues - on big sites we'd use a manage fleet of AP's that are all more or less the same and managed from a single platform.

Channel 100 is one of the "DFS" channels (which have some special handling in the presence of RADAR) you could maybe try experimenting with one of the other non-DFS channels (48 or lower.)

It may be that you are suffering interference from a neighbour. Again, not much you can do about that, but you could take a survey and see if you can devise a channel plan that either avoids them completely or avails the best "signal margin" (difference between you and them if on the same channel.) Trouble is, a lot of people leave their kit set up for auto-everything out of the box, so you might find a carefully designed neighbour avoiding channel plan falls to pieces weeks/months later if the neighbours' kit re-tunes for some reason.

@redmike5 - your settings look fine, I doubt there's anything you could change on your routers to make it work better. It is what it is.
Thanks Mick. I have tried 3 mobiles (iphone, an older Samsung and new Redmi) and all suffer the same symptoms. Going from secondary to primary is seamless, no intervention required and it would seem that connection doesn't actually drop. I suppose I could test this further, but it is purely academic now, as the in the opoosite direction, from primary to secondary, it simply doesn't work.

I tried your suggestions. I uses inSSIDer to check for interference. There is some on the 2.4G band, but no other networks reach the back of the house in the 5G band.
I disables other protocols on both routers and only allowed N on 2.4G and AC on 5G - no difference.
I moved 5G to channel 48 on the secondary - no luck.
I also tried using 2.4G only on both routers and then the 5G only to find out that it makes no difference at all.

So I am ready to cut my loses and just use the VR600 to broadcast wifi and SH3 in modem mode. If I get few more meters of coverage, I should be ok.
Thanks for your help anyway.
 

mickevh

Distinguished Member
That would suggest to me that one of your routers is not handling the re-association process very well, but we'd have to get into some packet traces and detailed analysis to know for sure.

Unfortunately, even if we can find culpability in a particular router, there's nothing we can do about as it's highly unlikely to offer us any control over the process - it's essentially baked into their OS. We could try moaning at the vendor and ask them to investigate and fix any problem, but there's not much chance of them doing that unless it's affecting lots of customers.

We could have a look and see if there's a newer firmware that addresses the issue, but I wouldn't just slap on the latest and hope for the best - so doing is little better than guessing and could even make things worse. It's perhaps worth a go when all else has failed and it's the "last thing to try" before chucking the device and trying a different one.

The only practical unilateral option would be to try something else and see if it works better.
 

redmike5

Novice Member
That would suggest to me that one of your routers is not handling the re-association process very well, but we'd have to get into some packet traces and detailed analysis to know for sure.

Unfortunately, even if we can find culpability in a particular router, there's nothing we can do about as it's highly unlikely to offer us any control over the process - it's essentially baked into their OS. We could try moaning at the vendor and ask them to investigate and fix any problem, but there's not much chance of them doing that unless it's affecting lots of customers.

We could have a look and see if there's a newer firmware that addresses the issue, but I wouldn't just slap on the latest and hope for the best - so doing is little better than guessing and could even make things worse. It's perhaps worth a go when all else has failed and it's the "last thing to try" before chucking the device and trying a different one.

The only practical unilateral option would be to try something else and see if it works better.
Thank Mick. I spend another night or two trying various combinations of settings, but nothing helps. Both routers run on the latest firmware, so updating was not an option. All in all, I decided that running the VR600 as AP was not an option.
So moved to plan B and I put VR600 it in place if the SH3 to provide wifi and run the SH3 as modem only. And TBH the increase of wifi signal strength was so modest, that I decided to retire the VR600 completely.
In the meantime, I've got my hands on an old N range access point and I set this up as range extender last night. With the limited testing I've done so far, signal strength is excellent and roaming is seamless. So far a success. Let's hope it all holds together.
 

Joe Pineapples

Distinguished Member
I hope someone can help. My primary/internet router is a BT HH6, and I'm trying to add an old Sitecom WLR-2100 to extend the wifi upstairs. I've gone into the HH6 and made a note of the LAN addresses used, and the address range set by the dhcp server. Having done that, I've logged into the Sitecom (sitecom + configuration pc via ethernet), changed the LAN ip address, but after doing this the pc no longer sees the sitecom, even after a reboot of both. Any ideas?
 

tom 2000

Distinguished Member
I hope someone can help. My primary/internet router is a BT HH6, and I'm trying to add an old Sitecom WLR-2100 to extend the wifi upstairs. I've gone into the HH6 and made a note of the LAN addresses used, and the address range set by the dhcp server. Having done that, I've logged into the Sitecom (sitecom + configuration pc via ethernet), changed the LAN ip address, but after doing this the pc no longer sees the sitecom, even after a reboot of both. Any ideas?
Did you do the other basics as set out in post 1 and did the settings stick? Bottom line does Sitecom allow access to network and internet?
 

Joe Pineapples

Distinguished Member
Did you do the other basics as set out in post 1 and did the settings stick? Bottom line does Sitecom allow access to network and internet?

It appears to be working now. This time I made sure to leave the ip address as the last thing to change in the Sitecom. Again the pc wouldn't see the Sitecom, even after a reboot of both, but I tried it physically on my network anyway. I can access the internet via its wifi, and I can now log in to it with my main pc, and see the settings I did are still there. Happy days. (thx OP)
 

The latest video from AVForums

Sony Bravia XR A80J OLED TV Review
Subscribe to our YouTube channel

Full fat HDMI teeshirts

Support AVForums with Patreon

Top Bottom