11

I am the admin of an apartment building. We are migrating from our crappy setup to a Ubiquiti setup. I am therefore performing an audit on the network topology. Here is the current setup:

Router (basement)
|
Switch (Basement) -- I realize this is redundant, but it is done for IP Cameras
|
Switch (Floor 1) - One cable per router 3 total
| (connected to switch on floor 1)
Switch (Floor 2) - One cable per router 3 total
| (connected to switch on floor 2)
Switch (Floor 3) - One cable per router 3 total
| (connected to switch on floor 3)
Switch (Floor 4) - One cable per router 3 total

I was wondering if it'd be better to have one cable for each floor, instead of daisy chaining to the previous floor. Each floor will have a POE switch to provide required power.

Please let me know if I need to clarify anything, I did my best to describe it.

Additional: * My primary concern with individual wires would be length of wire (3rd and 4th floor), the building isn't terribly tall but I don't want to run into other issues. Will this be an issue?

  • There is presently gigabit switches on each floor.
  • We provide a 50Mbit connection and I want to use the built in bandwidth management to limit the connections.

Thank you all for your input. At this time, we will probably leave the wiring alone to prevent breaking things. I purchased 1000ft of good quality cat5e (non-CCA). If we get another internet connection, I'll run one to the third floor, separating the first and second.

  • AFAIK, you don't want that many routers. Use access points that don't do routing. – user20574 Jul 13 '16 at 6:42
  • 1
    Consider carving out a separate network for your IP cameras (physical or logical). Critical infrastructure like that should be segregated from general public access. – user2320464 Jul 13 '16 at 18:55
22

Although it works, cascading switches leads to possible poor performance down the chain. Everyone on the fourth floor is sharing the uplink to the third floor, the same goes down the line... In addition to that, this introduces more points of failure. If the switch on floor two fails, everyone from 2-4 loses their connection.

Hire a professional technician to wire all the floors to a patch panel in the basement. That way you can have one switch to manage all the connections. This makes life much easier.

  • My only concern about the one wire per floor would be wire length, anything to be concerned about? I usually do relatively short runs in the buildings I work. – Thomas Jul 12 '16 at 18:23
  • 11
    The maximum length of Category 5 and 6 cable is 100 meters. That should be plenty of length for a 4 story building. – Keltari Jul 12 '16 at 18:25
  • 1
    I have to present this to the owner of the building and she is a stickler:)) So my question is, since I'll be limiting the bandwidth anyway, is even worth changing now? Everything has worked fine for years and no major issues. I'm just replacing the outdated hardware with more reliable stuff. – Thomas Jul 12 '16 at 18:32
  • 2
    if no one is complaining, then I wouldnt worry about the cascading switched. That cal always be changed later – Keltari Jul 12 '16 at 18:34
  • I figured the APs can only do 100Mbps anyway. I have gigabit in between so the uplink is strong. – Thomas Jul 12 '16 at 18:40
9

The first thing I'd do would be to get rid of the daisy chained switches, and have each floor feed into a master switch. This would ensure that every floor has the same amount of network hops to the router, and any network faults doesn't split the building in two.

Seeing as you already have a switch in the basement, this could be used as master switch, provided that you have enough ports, and that it has the capacity. I wouldn't go for anything less than gigabit here).

From the way I read your schematic, each switch has 3 wireless routers attached to it. Consider using these as access points only, so that the entire building is on the same subnet. Alternatively, one subnet per floor. This would allow for easy interaction between computers across floors.

  • Thats why I'm moving to the ubiquiti access points. Currently they are modded wrt54g's with dd-wrt in access point mode. – Thomas Jul 12 '16 at 18:21
  • @Thomas wrt54g are good routers which support working as AP only, at least if you use the tomato firmware. However, these access points are aging so I agree that they should be replaced. I don't have any experience when it comes to Ubiquiti, as I've mostly used Moxa for large scale implementations, so I cannot say anything for or against your choice in hardware. – Jarmund Jul 12 '16 at 19:01
  • i need the better bandwidth management and the reception is really lackluster. – Thomas Jul 12 '16 at 19:03
  • @Thomas that's mainly why I replaced my wrt54gl last summer. I'm currently using two Moxa AWK-5232 that I've borrowed from work as my private APs. As for the bandwidth management, that's all done on the main router. – Jarmund Jul 12 '16 at 19:07
  • 2
    Considering that this is an apartment building, not an office building, I don't think that there's much desire for "easy interaction between computers across floors". If I'm in 3B, I sure don't want the guy down in 1A having easy access to my hardware. If we're related or really good friends, then it's up to me to allow him access, not the building's infrastructure. – FreeMan Jul 13 '16 at 14:41
7

To give a solid answer, we'd need more specifics. How tall is 'terribly tall'? Ideally, you'd take the building's drawings/blueprints and map the planned runs to determine length. How many wired clients do you estimate?

Based on what you've said, I'd estimate that you need just one switch in the basement with Cat5 or Cat6 run to each access point location. A properly terminated and tested 300' cable run will work just fine, and having only one switch sounds much more desirable in your situation, since you will only have to buy, manage, and eventually replace one.

You also need to either research local codes or hire a professional to avoid creating fire hazards. At a minimum, you need CMR-rated (CoMunications Riser) cable for vertical runs. Some codes also require conduits and/or fire stops.

Alternatively, if you must have switches all over the place, consider connecting them back to the central node with fiber. It's a little trickier on the front end but allows for very long runs and is less prone to long-term issues like lightning and corrosion. Fiber's also dirt cheap these days.

3

If you're dealing with 50mbps, the gigabit Ethernet is extremely unlikely to be the cause of the current setup's problems. (Presumably it has some, or you wouldn't replace it or call it crappy). You should mostly focus on getting the radios right: make sure there is good signal strength & SNR throughout the building, channel overlap minimized to the extent possible, etc.

I think the ideal layout for your network would be to have all 12 access points wired to a patch panel in the basement, all connected to one switch. (If that's not doable because it'd require cable runs > 100 meters, then a 2nd switch on the 3rd or 4th floor.) The main advantage there is that you can troubleshoot from one place (no more running between floors to check link lights), you can use one UPS to provide backup power to everything, and it's easier to manage one switch instead of 5. You also have fewer points of failure.

But I'd definitely spend the budget on improving radio coverage first.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.