Where do I begin to look for main Internet Backhaul

Discussion in 'Wireless Internet' started by Jacobs Scooter, Oct 5, 2004.

  1. Each fall the very rural county to the north of me holds a very very
    popular 10 day festival that is estimated to feature 3000 vendors and
    draw 1.2 million visitors. Because of its rural location and low
    populatin density one of the participating "towns" (pop: 80) which
    hosts a majority of these vendors has no high speed broadband service.
    We think we could cover the entire area (2 square miles max) with
    802.11g WiFi by using several Firetide HotPoint 1000R Outdoor Wireless
    Mesh Routers along with D-Link AirPremier DWL-2700AP Wireless Outdoor
    Access Points. The only problem is I'm not quite sure where to find
    the Internet backhaul we'll need to run the whole mesh network.

    Where do I start? Are there utility maps that list underground fiber
    that can be tapped? Is there an office or company that I call to see
    how far the nearest T3 or T1 line is? How do I bring the signal from
    the nearest T1 or T3 (which is certain to be miles away) to this tiny
    town and into our mesh network? Am I thinking too small with just this
    town or should we be thinking about setting the whole county up with
    WiMax? What about satellite broadband if no other source is
    available? Will that be able to handle 2,000 + simultaneous users with
    speeds at 700Kpbs+? I've looked and looked on many websites and there
    just seems to be so many ways of doing this I'd appreciate some input
    from you "real worlders" out there with the experience.

    Any suggestions on the best way to accomplish this task would be
    tremendously appreciated. Thank you all for any assistance you could
    Jacobs Scooter, Oct 5, 2004
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  2. I'll try to keep it simple because of both your *and* my limited
    knowledge on this. But I may have had some more experience than you. You
    don't dig a hole and tie into the backbone, it simply doesn't work that
    way. You can call one of the major phone companies and ask them for
    their rates for whatever bandwidth you want, but when you start thinking
    of 2,000 plus users, you are looking at MAJOR expense. I'd say that
    probably a T3 (45Mbs) would be inadequate, but I've never tried that
    many connections at once. A T3 in my area from a tier one provider runs
    about $5,000 per month and that's on a one year contract.

    And no, there ain't no friggin way that a satellite connection could
    help you out with connecting 2,000 clients.

    From what I can tell from your post, you are getting in WAY over your
    head and the chances of success are well below slim. You need
    professional engineering and a lot of time to do a project like you
    suggest, not because I think the engineers need the money but because
    the problems you'll face would overwhelm you very quickly.

    Maybe if you rein in the scope of your plans you might make a favorable
    impression on everyone. Set up two, three or so hotspots where vendors
    and tourists can go to get online at broadband speeds. They'll
    appreciate something like that if it works much more than a huge project
    that never gets off the ground.
    =?ISO-8859-1?Q?R=F4g=EAr?=, Oct 6, 2004
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  3. You're in over your head. Get some expert help. 3000 vendors do not
    suck 700Kbits/sec each. They use it for credit card machines that
    work just as well at 1200 baud and move very little traffic. What
    will kill you is the one idiot that uses your network to redistribute
    his lastest virus or worm, or the inevitable video conference. Most
    of the traffic will be VoIP (phone calls), email, and Ouchlook
    replication. Ask someone that's run one of these event for a traffic
    summary. My guess is that you could do it with one or two T1's.
    Well, if you had bothered to disclose the name and location of the
    event, I could have looked up the name and location of the nearest
    ISP. Even though the town is small, there are usually nearby towns
    with big ISP's. You give them a call, arrange for some temporary
    bandwidth at exhorbitant charges (mostly setup time). Then, you get a
    wireless backhaul point to point bridge (usually at 5.6GHz) to deliver
    the bandwidth to the fair. The first box it hits is the bandwidth
    manager. You don't want one user hogging ALL your bandwidth.
    Therefore, you need someway to control bandwidth use by application,
    IP address, and traffic pattern. Search Google for "bandwidth

    Lose the mesh network. If you really have 3000 users in a relatively
    small area, the very last thing you'll need are bandwidth wasteing
    store and forward repeaters. Put some access points around the
    perimeter (where you can get to them without getting trampled) and
    connected with a fiber ring for redundancy. Power should be locally
    supplied (gel cell with solar charger) so you don't have to run AC
    power or generators. Antennas should be 90-120 degree sectors pointed
    inward. No sense in illuminating areas that don't need coverage.
    Take a map and build up a channel plan so that you don't have any
    overlap. Use one SSID for everything and forget about roaming. It's
    too difficult to get right and not worth it for the few that need it.
    Just have them re-connect.
    Ummmm.... You don't "tap" fiber. Try that and the owner of the fiber
    will have you drawn and quartered. You need to find a location where
    all the fiber comes together where it can be run through a repeater
    and splitter. That's usually at the local CATV company or telco
    central office.
    Actually yes.
    When you locate the local central office, you'll see a list of their
    capeabilities and available services. The catch is that T1's and T3's
    tend to be maxed out and will require an upgrade at the CO to supply.
    The monthly costs are exhorbitant, but wait until you get the
    installation charges. That's why you want to borrow bandwidth, not
    arrange for a new connection.
    Lose the mesh network. It won't work with such density. The usual
    way is with wireless point to point radios. Do it on 5.6GHz so that
    you don't trash the 2.4GHz band for the users.
    If you decide to shovel encapsulated ethernet to the ISP's router,
    instead of a raw T1 or T3, make sure your wireless bridge can handle
    the large number of MAC addresses (one per client) that the system
    will need. This eliminates all of the cheapo bridges on the market
    which usually max out at 32 MAC addresses. Even the fancy ones
    (Alvarion, Lucent/Proxim) will max out at 256 MAC addresses. If you
    do your own routeing, this is not a problem.
    You can't buy functional 2.4GHz WiMax hardware unless you wanna be
    part of someones beta test.
    There are commercial satellite broadband vendors that will supply your
    necessary bandwidth. I don't have my list handy.
    Hell no. You don't need it anyway. I strongly suggest you carefully
    analyze your bandwidth usage and your topology as I'm sure you're
    over-estimating the type and magnitude of the usage.
    for the Wireless ISP mailing list. Lots of people with lots of
    Just one suggestion. Hire someone that has a clue or you'll burn big
    bucks on something that isn't gonna play. However, I am impressed
    that you're trying to tackle such a project. Best of luck and may you
    stay within budget. I'll post my list of satellite vendors when I
    find them.

    Some notes on the last BurningMan wireless network:
    Jeff Liebermann, Oct 6, 2004
  4. :If you decide to shovel encapsulated ethernet to the ISP's router,
    :instead of a raw T1 or T3, make sure your wireless bridge can handle
    :the large number of MAC addresses (one per client) that the system
    :will need. This eliminates all of the cheapo bridges on the market
    :which usually max out at 32 MAC addresses. Even the fancy ones
    :(Alvarion, Lucent/Proxim) will max out at 256 MAC addresses. If you
    :do your own routeing, this is not a problem.

    Small point: the Cisco 340 and 1100/1200 series are spec'd at more
    than 2000 MAC addresses... but I don't think I'd really want to try
    running even a fraction of those!
    Walter Roberson, Oct 6, 2004
  5. Not so small point. Cisco 350 VxWorks firmware before 12.04 barfs on
    anything over about 127 MAC addresses:
    CSCeb61728 — The access point no longer hangs and reboots when
    an abnormally large number of clients are associated.
    That drove me nuts for about 3 months until I figured out what was

    This feature:
    CSCin46639 — When configured to do so, the access point now
    switches to repeater mode when Ethernet link is down.
    also provided endless entertainment value as unplugging an ethernet
    backhaul instantly caused wireless traffic to slow down by 50%.

    (Moral: Read the release notes to avoid surprises).

    Incidentally, the usual trick is to put 3 radios on each pole on
    channels 1, 6, and 11 to deal with the problem. With 256 MAC
    addresses per radio, chances of running out are low, especially if the
    access point is sufficiently smart to expire stale MAC addresses as
    fast as possible. With a fake roaming type of arrangement, this is
    possible using fairly short expiration times. The users will see
    disconnects if they go idle, but will reconnect almost instantly, so
    it shouldn't be a problem.

    I also forgot to mumble something about network management and SNMP.
    These are nice because you can keep track of what each radio is
    actually doing, which radio is getting abused, and who's connected to
    what. All this can be done from a central location. With SNMP, you
    can also change settings, but that's best done by a web browser

    Of course, there should be some way to do authorization and signup to
    insure that evil bad guys (like myself) don't just reconnect when you
    try to pull their plug. Some of the hot spot software will work but
    might require a RADIUS server to work. Of course, you could just
    trust everyone to do the right thing, but the first bozo that shows up
    with a virus or worm infected laptop will ruin that idea.

    There's no way that I know of that someone can setup a big wireless
    LAN, fire up an IDS (intrusion detection system) and just walk away.
    Someone has to watch the traffic and play policeman. With the proper
    network mangement tools, it's much easier to do this.
    There are lots of others.
    Jeff Liebermann, Oct 6, 2004
  6. Jeff,

    As always I count on you for brutal honesty and you never disappoint.
    Thanks for the advice and input. You all have undoubtedly saved me
    tons of time and money. We are doing market research over the next
    week and that will indicate what kind of "demand" we are looking at in
    the first place so that should tell us a lot about being able to scale
    down the project.
    Jacobs Scooter, Oct 6, 2004
  7. Also, is there a consulting company that you all might recommend to do
    a feasability/site survey study of the area? I'm sure if I ask 5
    different companies they will all have 5 different ways of
    accomplishing this so I am looking for some recommendations.

    Jacobs Scooter, Oct 6, 2004
  8. Oh goodie. I get to plug my friends, favorite vendors, and

    Marlon Schafer
    Marlon's been around since the stone age and knows

    Jack Unger
    Jack gives mostly lectures on Wireless ISP techniques, but knows
    everyone in the business (with a clue).

    If they can't fly to your unspecified location, they will certainly
    know who can do the engineering for you, hopefully in the area.

    You might also wanna contact the vendors that carry a wide range of
    hardware. Ignore the usual sales pitch and concentrate on the names
    and enginnering.
    They will have the names of dealers, groups, and individuals that have
    already done portable wireless and fairs.

    Incidentally, I can think of at least 10 (not 5) radically different
    ways of doing the wireless, including a few that have probably never
    been tried. I've always wanted to try my "leaky waveguide" method of
    "plumbing" the area. Maybe a tethered helium balloon mounted access
    point or repeater. Perhaps an inflatable tower:
    Jeff Liebermann, Oct 6, 2004
  9. Of the two I found Jack to be far more accessible to the non-RF engineer
    type. Not really putting Marlon down, but seems he's too busy to deal
    much with people starting out in wireless.
    =?ISO-8859-1?Q?R=F4g=EAr?=, Oct 7, 2004
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