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Doday
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 T1 capacity
I have a question that maybe someone can help me with. It is probably just a math problem
I was looking into more info on T1 and T3 lines and came across this statement on a site which seems to know all about them called everythingT1:
"Most small Internet providers have a T1 (or a fractional T1) line as their connection to the Internet. A Full T1 should accommodate from one to over 200+ users and other services from an Internet provider. "
How can this be true if 200 user with 56 Kbs bandwidth each. Multiply this by 200 and you would need 10.2 Mbits, far more than the 1.54 Mbits offered by a T1 connection?
Thanks in advance.
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 02-08-02 02:21 PM
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freak
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the key here is that most internet users you sell your service to do *not* connect at the same time -- at least it is that ISP's gamble... just ask AOL 
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02-08-02 02:40 PM
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Doday
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But if my math is correct that means that really only 27,5 users could use a T1 line at any given time. This seems impossible.
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02-08-02 02:44 PM
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freak
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As I said.... just ask AOL
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02-10-02 04:02 PM
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Doday
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02-10-02 06:28 PM
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freak
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you're welcome. Sorry about the nasty speed -- or lack thereof
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02-10-02 08:47 PM
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gammann
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You are also assuming that every 56k user is using their maximum 56k pipe all the time, which isn't the case. Data is very bursty.
For instance, when you check your email, it connects to the server, downloads the new mail, then your connection sits idle while you read. When you stop to read a webpage that frees up bandwidth for someone else.
Overselling bandwidth is how money is made. What sucks is its done at every level. Your ISP may have a T1 to their SP, which then connects 100 T1s over a single DS3, which then connects to a Tier1 provider with 10 other DS3s over an OC3 ATM link.
AOL has other issues besides overselling bandwidth.
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02-12-02 06:10 PM
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freak
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quote:
Originally posted by gammann
You are also assuming that every 56k user is using their maximum 56k pipe all the time, which isn't the case. Data is very bursty.
AOL has other issues besides overselling bandwidth.
Very good points! 
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02-14-02 12:39 AM
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