On Tue, Feb 17, 2009 at 9:55 AM, Ed Quinn <[email protected]> wrote: > > I'm looking for some free advice and was referred here by an expert. > > What I'd like to set up is a link between two data centers. The idea > is to connect two clustered hosts running a DEC operating system that > provides load-balancing and volume shadowing across cluster members. > I run that O/S at only one office in Portland right now but I'm trying > to develop a disaster-avoidance concept. > > The software specs call for a 10 mbps or better link so a cheap > 802.11g bridge looked good on paper. Location 1 is on a hillside with > an unobstructed line of sight to a neighborhood three miles away and > about 100 feet lower in elevation. I've got a couple Ubiquiti Bullet2 > wireless units (2.4GHz) and am thinking about getting a couple 24dBi > grid parabolic antennas such as Pacific Wireless DC24HDPF1PF-EZ. If I > could get a couple laptops talking reliably then I'd have a demo for > my boss. If not, then I'd have some almost-new gear to contribute to > a worthy 501(c)(3) organization.
I can see how that looks good on paper, and it will be interesting to see your results in the real world. My experience has been that the real world is much less forgiving than paper, and I think that 10 Mbps at that distance is likely a pipe dream. Real world performance with 802.11g, in the environment it was designed for (home or office), is generally 20 Mbps or so. At the range you're considering, I'd think 3-4 would be the absolute top, but since you have the gear, it's worth trying. This 501(c)(3) would love to hear your results, and accept the gear if it fails to perform to your needs. You might even be able to convince some curious members of this list to help out with your test... > So before I go embarrass my self too seriously I wanted to get your > reaction. Would a setup like this be supportable from a networking > point of view? Or should I be looking at heavier artillery? Pointers > to FAQs are welcome, too. You might try it with some 802.11a gear, to get into the less cluttered 5GHz spectrum, though all things being equal (which they aren't), the higher frequency of 11a is not as good over distances as 2.4GHz. There are, of course, some licensed bandwidth options, but then you're talking orders of magnitude more expensive, though if your alternative is to get fiber between the sites, that may still work out to your advantage. If you decide to go that direction, you'll want to contact someone like Invictus Networks to bid a system. -- Michael Weinberg President Personal Telco Project, Inc. A 501(c)(3) Non-Profit --~--~---------~--~----~------------~-------~--~----~ The Personal Telco Project - http://www.personaltelco.net/ Donate to PTP: http://www.personaltelco.net/donate Archives: http://news.gmane.org/gmane.network.wireless.portland.general/ Etiquette: http://www.personaltelco.net/index.cgi/MailingListEtiquette List information: http://lists.personaltelco.net To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] -~----------~----~----~----~------~----~------~--~---
