Need help with network design for large ranch

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Need help with network design for large ranch

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Need help with network design for large ranch
Need help with network design for large ranch
2020-06-16 17:59:00

I used to consider myself pretty up on networking design and technology 30 years ago, but my skills have clearly atrophied :(  Thus a series of question that I hope will not annoy too much.

 

I am installing an outdoor wifi network on a large (50 acre or so) rural site that is quite mountainous and forested.

 

The site basically has two "halves", separated by a forested gully.

 

I want to use EAP-225 Outdoor AP's on each half (likely 3-4 on each half), some hardwired to each other and some in Mesh mode, and to connect the two halves using CPE-210's.  I chose 2.4 GhZ for superior penetration of the foliage, and so far that seems to be proving out.  I have verified that the CPE-210's can connect over the roughly 1/4 mile link between the two "halves."

 

My question is how best to configure the various AP's.  In a perfect world, I would like a single SSID and a single IP namespace across the entire property.

 

Do I put one CPE in AP mode and the other in client Mode?  I tried that, but it doesn't seem to work :( (where "work" is defined as allowing connectivity across the link - they connect just fine, but the WAN section of the client is blank).

 

Using the same SSID that I use on my EAP-225's that devices connect to? 

 

Just assign the same SSID to each EAP-225 and give each one a unique static IP address?

 

How do I configure the EAP-225's into mesh mode?

 

Thanks much!

 

 

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#1
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Re:Need help with network design for large ranch
2020-06-17 01:17:18

@DanL 

 

In case my question wasn't clear, here is a picture of the planned topography.  Each EAP-225 will actually be the root AP for a mesh of other EAP-225's, but I don't think that matters.

 

The key questions are:

 

- What SSID should the CPE-210's use?  The same as the EAP-225's that provide client access, or a special SSID that is just for the PtP link?

 

- What IP addresses should the CPE-210's use - same IP namespace as the rest of the network, or a different one (ie different subnet)?

 

- What mode should each CPE-210 be in?  I assume AP for the one hardwired to the switch and Client for the "remote" one.

 

Thanks much!

 

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#2
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Re:Need help with network design for large ranch
2020-06-17 14:04:22

Hi @DanL,

 

Wow, sounds like a cool project!

 

You're definately on the right track.  You'll want to add an OC-200 to the mix or have a dedicated PC on which to run (the free) Omada server.  This will greatly simplify your ability to configure and managed all of the EAP225's, SSID', MESH, etc.  But, it won't manage the CPE210/510's -- you'll need to use their web UI's for that.

 

You're best bet is to configure the CPE's as separate PtP airlinks (e.g. dedicated wireless backhaul).  Give them their own SSID and password, and don't share this information with guests.  In order to prevent accidental mis-communitcation it's probably best to use a separate SSID for each pair of CPE's.

 

Guest / end user Wifi SSID's would be separate, and can be whatever you want.  You can centrally manage all of this via Omada/OC-200.  And configure them whatever would work best for your application -- 2.4 only, 2.4 and 5.8 separately, or 24 & 58 with band steering.  Keep in mind that EAP's which are wirelessly MESH'ed with a CPE connected root node all share the same 5.8GHz backhaul (per root node).  So any mobile clients (aka STA's) will be competing with this backhaul if you let them use the 5.8GHz channel.  So if you're going to have several (e.g. 2 or 4) MESH'ed AP's per root node, it's best to limit clients to 2.4GHz, unles you only have a small handful (<5 or 10) of them.

 

All devices can be in the same IP address space, clients, EAP's, and CPE's.  DHCP services, routing, NAT (to your cellular uplink) would all be handled at a central point -- where your internet connection is.  UNLESS you decided to break your two separate "halves" completely and use separate Cellular uplinks for each.

 

You can use VLAN's for out of band management (of the EAP's) and or separate VLAN's by SSID for added security.  But you would need to have a Layer 3 switch to handle this at a central point.  I'm also not entirely sure how this would be handled going through the CPE's.

 

CPE and EAP wireless MESH throughput is not that super fast, but if you're using cellular for broadband connectivity this woudn't be your limiting factor.

 

EAP's can use either DHCP or manual.  I use DHCP at home, but manually assigning them to a specific range is generally best practice from a documentation perspective,  How many total devices and clients are you expecting?  Less than 255?

 

I don't have a lot of experience with the CPE's but R1D2 does here o nthe forum, I'm sure he'll respond with some additional suggestions.

 

-Jonathan

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#3
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Re:Need help with network design for large ranch
2020-06-17 22:40:42

@DanL Thanks much Jonathan, very helpful!

 

Now I just have to get the CPE-210's working properly and wait for the arrival of my Omada controller.

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#4
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Re:Need help with network design for large ranch
2020-06-18 12:26:13 - last edited 2020-06-18 12:27:30

 

DanL wrote

- What mode should each CPE-210 be in?  I assume AP for the one hardwired to the switch and Client for the "remote" one.

 

JSchnee21 answered most of your questions already, here are some recommendations for the PtP link with CPEs:

 

Operation modes of the CPEs should be AP mode and Client mode. WAN is not used at all (no routing).

 

Settings of the CPEs should be:

 

  • 802.11n-only WiFi mode,
  • 20 MHz channel width (or 40 MHz, but see note below),
  • MAXtream off,
  • distance setting either Auto or real distance + 0.1km,
  • front side of the CPEs (antennas) need to be precisely aligned to each other to get best results (use CPE's Antenna Alignment tool).

 

Note: 40 MHz channel width requires 8 channels in the 2.4 GHz band, so CPEs will need to share overlapping channels. You can avoid this by using 20 MHz channel width. Even in a rural area I would rather use CPPE510, which allows for non-overlapping channels in the 5 GHz band at 40 MHz channel width.

 

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#5
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Re:Need help with network design for large ranch
2020-06-18 13:00:44

Hi @DanL,

 

You have two pair of CPE's right?  One pair for one half of the ranch, and one pair for the other half?  Are the two broadband connected CPE's on the same mast?

 

If they are mounted separately (on separate masts with some separation in between -- like on opposite sides of a building) there may not be much / any 2.4GHz signal interference between them.  The antennas are highly directional and the amount of signal behind/around the CPE is much less (but not zero) than in front of it.

 

So you could, potentially, experiment with setting one to channel 1 (40MHz, which is 1 & 6) and the other to channel 6 (40MHz, which is 6 & 11).  Yes, there would be overlap here, but it may be minimal.  But, you would still have additional 2.4GHz interference from the client side EAP Wifi on the 2.4GHz band which would be set to 20MHz on channels, 1, 6, or 11 (or multiple depending on how many EAP's you have).

 

5 GHz does have more open channels -- two @ 80Mhz, 4 @ 40MHz, and 8 @ 20 MHz.  The EAP's will be using 5.8GHz for backhaul, but this may be less of an issue since all of the wirelessly MESH'ed EAP's on a single root node use the same channel.  MESH backhaul will either be channel 36 or 149.  You could then set the CPE to use the other channel.  I'm not sure if the CPE510 supports 80MHz BW or only 40MHz.  I thnk 40, b/c it's 802.11n -- but I'm not 100% sure.

 

Regardless, you could then alternate channels something like this:

 

Left Half of Ranch

EAP225 Root Node on ch 36, 80MHz

CPE510_1b on 149

 

Center of ranch (with internet)

CPE510_1a on 149 (for left half)

CPE510_2a on 36 (for right half)

 

Right Half of Ranch

EAP225 Root Node on ch 149, 80MHz

CPE510_2b on 36

 

OR assuming the CPE's don't do 80MHz, you could split the lower (36) or upper (149) range into two 40MHz halves (e.g. 36 & 40; 44 & 48), use them for the CPE's, and then use the other range (e.g 149) for your root nodes in each of three locations -- (left half, center, right half) -- assuming you want to have Wifi in the "middle" too.

 

Left Half of Ranch

EAP225 Root Node1 on ch 149, 80MHz

CPE510_1b on 36 & 40

 

Center of ranch (with internet)

CPE510_1a on 36 & 40 (for left half)

CPE510_2a on 44 & 48 (for right half)

EAP225 Root Node3 on ch 149, 80MHz

 

Right Half of Ranch

EAP225 Root Node3 on ch 149, 80MHz

CPE510_2b on 44 & 48

 

As long as the EAP "clusters" are ~100-200 Meters away from each other, they can be on the same channel and not see each other to cause interference.

 

-Jonathan

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#6
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Re:Need help with network design for large ranch
2020-06-18 16:06:04
Very helpful, thanks!
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#7
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Re:Need help with network design for large ranch
2020-06-18 16:06:47
No Jonathan, just one pair of CPE's. There are just two halves of the ranch, not three lol. You have center left and right, but there are just left and right... Your ideas re channel selection are very helpful, thanks much!
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#8
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Re:Need help with network design for large ranch
2020-06-18 17:53:13

@DanL, oh, I also did mis-understand this point. If you have just one pair of CPEs, you can use 40 MHz channel width.

 

Anyway, mounting two CPEs of two pairs on two poles apart from each other won't eliminate interferences at all if the four CPEs use the same channels at 40 MHz channel width.

 

Antenna beam width of a CPE210 is 65º H / 35º E which would require mounting the remote CPEs ~127m apart to avoid interferences over a distance of 100m. It's the remote CPE, which will intefere with one of the local CPEs (resp. the local CPE, which interferes with one of the remote CPEs), but not the two CPEs at the same location.

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#9
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Re:Need help with network design for large ranch
2020-06-20 06:01:16

@DanL 

 

Got things working today, thanks again for all the help.

 

S/N is currently only 20db, so going to need to keep working on improving that (raising the CPE's on either end higher will help the most I think, I moved one of them out from behind a tree today and that made a ~15 db difference).  But the link is up and stable and running at ~10 mbps, which is all that my lousy cellular backhaul can handle until Starlink gets their act together ;)

 

Very much appreciate everyone's thoughts!

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Re:Need help with network design for large ranch
2020-06-20 10:20:50

 

DanL wrote

S/N is currently only 20db, so going to need to keep working on improving that (raising the CPE's on either end higher will help the most I think, I moved one of them out from behind a tree today and that made a ~15 db difference).

 

Just for the record: directional links are very sensitive to any obstacle inside the fresnel zone. You need at least 40% fresnel zone clearance and a SNR of 25dB or better for a reliable directional link.

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#11
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