I am planning on supporting about 20-30 clients on one T1. 1M is up to 1M, and you will probably not see it very often. I have a good friend that runs a small ISP and hosting co. and he says a T1 could probably support even more. I am planing on taking it slowly so I don't make too big of a flop! I will probably just start with a DSL line until I have 5 or 6 customers.
I am planning on supporting about 20-30 clients on one T1. 1M is up to 1M, and you will probably not see it very often. I have a good friend that runs a small ISP and hosting co. and he says a T1 could probably support even more. I am planing on taking it slowly so I don't make too big of a flop! I will probably just start with a DSL line until I have 5 or 6 customers.
what do you mean UP TO? what? forget it... _________________ WRT54G 3.1
DD-WRT v23 SP1 Final (05/16/06) std
How Much Internet Bandwidth Does My Town
Really Need to Build a Wireless ISP?
Mar. 21, 2006 - Welcome to the fourth article in BWE’s series of "How-To" articles that focus on how to build broadband wireless networks in areas that desperately need high-speed Internet connections.
This week's article is focused on how to select the amount of Internet backbone connectivity you’ll need to lease in order to transport your wireless network's traffic to and from the Internet.
The most common type of telecommunications circuit that a Wireless ISP (WISP) begins with is a T1 circuit, which carries full duplex traffic at 1.5 Megabits per second (Mbps).
A T1 circuit usually can support a network of around 100-200 users depending on their bandwidth requirements. This doesn’t mean that all 200 subscribers can get a full 1.5 Mbps connection at the same time.
Most WISPs over subscribe their network on a 6:1 ratio. This means that for every six customers, only one of them will be online at a single point in time. So if you have 200 customers that would mean that normally only 33 would be online at one time.
Now divide 1.5 Mbps by 33 and you’ll get around 45 Kilobits per second (Kbps), which isn't much better than a dial-up connection. The good news is that all users are not sending email or requesting web pages at exactly the same time.
The best way to know how much bandwidth you'll need is to use network monitoring tools that let you know when your users are approaching too much network congestion. Most network managers will set an alarm to go off when the network surpasses 70% congestion. This allows managers time to order more bandwidth before users begin to experience 100% congestion.
Recently a good price for a single T1 was around $500 per month. However, the FCC just made a ruling that could cause the price of T1’s to jump back into the $1,000 per month range.
Many WISPs start with a one T1 circuit to support a small wireless cell. Then they add a second, third and forth cell. About the time they add a fourth cell they are paying around $3,000 per month in bandwidth costs for four T1 circuits.
The next step is to move up to a DS3 circuit, which provides 45 Mbps of bandwidth and costs the same per month as 3-4 T1 circuits. Instead of feeding each cell with a single point-to-point T1 circuit, a WISP can bring the DS3 circuit to a centralized tower and beam the bandwidth wirelessly to as many cell sites as needed, which allows them to significantly expand their WISP’s coverage area.
One problem that exists in many rural areas is no accessibility of T1 circuits. In this case the only choice available will be a commercial grade satellite downlink. The monthly costs range in price, but are usually a much better deal than buying a T1 in a rural area. While fairly expensive, satellite uplinks from Loral Skynet or Broadsky Networks can provide a backbone Internet connection with enough bandwidth to make building a broadband wireless network in remote areas possible.
Please join us next week to learn, "How to Select the Right WISP Equipment for Your Town."
If you would like to read other articles in this series or an expanded version of this article you can read them online at: www.bbwexchange.com/howto/
The reason I can get a T1 so cheap is my base station is about 300 feet from the telephone central office
We've got a T1 at work that supports 100 wireless laptops and probably another 100 desktops. They're not all on at any given time, but at peak times I bet we get 125 users simultaneous. Each person gets around 150 KB/s down, which is hardly dial-up speed.
I hear that if I help support the developer, I can have access to a version of DD-WRT that includes bandwidth management. Is the DD-WRT bandwidth management advanced enough that I could use a script on each WRT54G to update all routers from a central machine when they reboot, and a script on the central machine to push new settings to the routers when a new customer signes up for one of three possible wireless plans (say 256, 512 and 768K)? Something like Sputnik Agent? I dont mind scripting, I have been using linux solely since 2000.
We've got a T1 at work that supports 100 wireless laptops and probably another 100 desktops. They're not all on at any given time, but at peak times I bet we get 125 users simultaneous. Each person gets around 150 KB/s down, which is hardly dial-up speed.
Do the math dude!
This is impossible.
150kbps * 125 = 18.750 Mbps
We've got a T1 at work that supports 100 wireless laptops and probably another 100 desktops. They're not all on at any given time, but at peak times I bet we get 125 users simultaneous. Each person gets around 150 KB/s down, which is hardly dial-up speed.
Do the math dude!
This is impossible.
150kbps * 125 = 18.750 Mbps
*** Do you really think EVERYBODY is loading a webpage at the same time? ***
That's the thing. If you are offering a service to paying customers, they are going to be expecting dedicated bandwidth. What makes you think your customers aren't going to download porn? Bittorrent? Of course we all know that a majority of the subscribers only use their connection for casual browsing, but if just 1 of those customers happens to use bittorrent, then you're absolutely screwed. Perhaps 1 of your customers is a gamer, and 2 of them are downloading a file. Do you think he or she is going to be too happy?
Office and small campuses typically use a T1 for their employees and students, but these are places where users are usually busy, and in most cases, limited to only HTTP.
A small community college nearby utilizes a T1 and around class times the network is VERY VERY slow. And this is only due to myspace. AKA ATROCITY
************** WHICH IS SHIT ********************* _________________ WRT54G 3.1
DD-WRT v23 SP1 Final (05/16/06) std
I have no experiance in this, and my guess is not many of you do either. So instead of arguing I will point you to someone I think know what thay are talking about... Broadband Wireless Exchange Magazinehttp://www.bbwexchange.com/howto/ read the whole thing, and espeacialy "How Much Internet Backbone Bandwidth Does My Town Need?".
Until I prove it to myself that they are wrong by actually trying it, I will plan on supporting about 30 customers on a T1. That is much less the the 100-150 they say is possible. Read it for yourself http://www.bbwexchange.com/howto/4_how_much_bandwidth.asp
Even DSL does not have dedicated bandwidth. If you buy a 1.5M DSL line, the 1.5M is the burst speed. Your downloads will be much slower than that. You are actually sharing a 1.5M T1 with 15 to 30 other people. DSL is just your part of a T1 split up between many people.
For the home user with a single personal computer. Burstable download rates up to 256K and upload rates up to 128K.
As low as $29.95
Quote:
**The maximum speed indicates burst speed at a maximum of 60 seconds unless connection is dedicated. Actual available bandwidth will depend on link quality, Internet congestion, server or router speeds, protocol overhead, or other factors. No minimum level of speed is guaranteed. Read our Wireless Broadband Policy for more information.
They know what they are talking about.. theoretically. The reality is that your users will consist of gamers, porn downloaders, P2P users, however the majority will only utilize the service for HTTP. Out of the 30 users you say you can get online, at least 1 of them (SEVERAL MORE) will be using one of these bandwidth intensive services. And just that 1 can ruin the service quality for all the rest.
If you were offering your services at hotspots you will most definately not have any problems as most of the clients will be on laptops and use it primarily for web browsing. When you start giving people access to the internet from their homes, that's when you start running into bandwidth issues due to previously mentioned services.
Are you going to limit bandwidth to each client to 256/128? That would be much less risky. _________________ WRT54G 3.1
DD-WRT v23 SP1 Final (05/16/06) std
Even DSL does not have dedicated bandwidth. If you buy a 1.5M DSL line, the 1.5M is the burst speed. Your downloads will be much slower than that. You are actually sharing a 1.5M T1 with 15 to 30 other people. DSL is just your part of a T1 split up between many people.
Please tell me whyan ISP would run a T1 (max of 1.5mbps syncronous) to a DSLAM and yet offer 6mbps packages?
Typically, an OC connection is running from the ISP to the DSLAM, and as long as the ISP doesn't over subscribe, you'll get your dedicated bandwidth.
The same goes for cable. From past experiences I've noticed the cable companies like to jam as many subscribers in as they can.
Bellsouth's DSL service has always been excellent. _________________ WRT54G 3.1
DD-WRT v23 SP1 Final (05/16/06) std
I have no experiance in this, and my guess is not many of you do either.
well I dont have experience as an ISP, but managing bandwidth supplied to large numbers of users I know all about. Looks like BG does too. At an office 90% of your traffic is going to be internal and perform the same no matter of your net connection. Your outside bandwidth is generally between your company's proxy and/or mail servers and the net. Those servers then serve inside clients via LAN.
My personal network has 4 users and net is fed by a 5mbps cable modem. None of us use torrent or p2p regularly, but there are some games. I pay $45/mo and expect that service for that price, but of course im in an area where I can get it...
If you want to give your customers 256/256 you would be looking at 6 customers to a T1 for a "fair share." There is a small amount of truth to your logic that not everyone is using it at once, but much more to BG's point of p2p. I wouldnt go more than 8 users on 1 T1 at 256/256.
And at that math you're still profiting 100% outside of non-bandwidth expenses.
