1 edit | If all use their limits at once, how does the cap help? said by espaeth:You have to understand that with the topology under which networks are constructed, links are sized to meet demand so utilization does have a direct impact on costs. Right, so how does an overall bandwidth cap help? Every subscriber could limit their data usage to 10GB/month, but if they all access the network at the same time to do it, you have a problem. | |
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  espaethDigital PlumberPremium,MVM
join:2001-04-21
Minneapolis, MN
kudos:2
 ·Vitelity VOIP
2 edits | If all use their limits at once, how does the cap help? said by neil0311:Right, so how does an overall bandwidth cap help? Every subscriber could limit their data usage to 10GB/month, but if they all access the network at the same time to do it, you have a problem. Every person in a city could flush their toilet at exactly the same time and cause a problem with water pressure within a city as well -- in general these things don't happen. Sure it's possible, and you could engineer capacity to handle it, but in most cases it just unnecessarily increases the cost of the infrastructure.
Monthly caps don't directly address point in time congestion. Comcast, in particular, already has a system to do that. The monthly caps are more about total capacity not being unlimited for the month. Each network segment has the ability to transmit {x} GB over the course of the month based on segment interface speed. Generally caps try to address preventing individual users from exceeding a certain percentage of that total capacity. (ie, preventing a single user from consuming 10+% of total shared capacity) It's just not economically viable to have a subscriber who is contributing 0.5% of revenue for a segment generating 10-15% of the demand; the whole thing goes sideways if left unchecked. Monthly caps are not a perfect solution, but it's an exception process. The vast majority (99.99+%) of subscribers don't get anywhere close to the cap. | |
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1 edit | What is the capacity/month of a D2 line? What is the capacity/month of a D2 line ? | |
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| | espaethDigital PlumberPremium,MVM
join:2001-04-21
Minneapolis, MN
kudos:2 Reviews:
·Vitelity VOIP
| Re: What is the capacity/month of a D2 line? said by sturmvogel:What is the capacity/month of a D2 line ? 38mbps * 60 sec/min * 60 min/hour * 24 hr/day * 30 days/month * 1byte/8bits = 12312 GB/mo. Factoring out 15% overhead: 10465GB/mo.
Average subscribers per channel in 1999: 1000. Average subscribers per channel now: 250.
You can do the math from there. | |
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| | | K PattersonPremium,MVM
join:2006-03-12
Columbus, OH
kudos:1 | Re: What is the capacity/month of a D2 line? The actual capacity is 43 something. The 38 is after the 15% so we're looking at 12,000 GBytes/month, or 48 users each consuming their 250GB "cap". | |
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2 edits | Re: What is the capacity/month of a D2 line? It would be a slightly lower percentage, but what does that mean? | |
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| | | | | | | Re: What is the capacity/month of a D2 line? said by nate1234:It would be a slightly lower percentage, but what does that mean? espaeth said "Generally caps try to address preventing individual users from exceeding a certain percentage of that total capacity. (ie, preventing a single user from consuming 10+% of total shared capacity)"
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Obama '08. Will help resolve the terrible broadband issues we have that put us so far behind other countries. | |
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| | | | | | | | Re: What is the capacity/month of a D2 line? so what does 2% mean? | |
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| | | | | | | | | Re: What is the capacity/month of a D2 line? 2% is considerably less than 10%.
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Obama '08. Will help resolve the terrible broadband issues we have that put us so far behind other countries. | |
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| | | | | | espaethDigital PlumberPremium,MVM
join:2001-04-21
Minneapolis, MN
kudos:2 Reviews:
·Vitelity VOIP
| said by sturmvogel:espaeth said "Generally caps try to address preventing individual users from exceeding a certain percentage of that total capacity. (ie, preventing a single user from consuming 10+% of total shared capacity)" The last person to get the call used 715GB.
715/12312GB = 5.8%
Assuming there are 250 people per downstream channel (based on averages), on an equal divide, that's 1/250 or 0.4%
So you have someone who represented 0.4% of the paying subscribers on that segment consuming 5.8% of total capacity.
I don't believe the 250GB cap was ever meant to be a true bandwidth allocation per subscriber, it's simply a point at which to look at taking action to stop the bleeding. | |
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| | | | | | | | | Re: What is the capacity/month of a D2 line? What happens to the capacity that isn't used? Does Comcast resell it? or Does it rollover into the next month? | |
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| | | | | | | | | | Re: What is the capacity/month of a D2 line? nothing? | |
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| | |  jlivingoodPremium,VIP
join:2007-10-28
Philadelphia, PA
kudos:1 | said by espaeth:Average subscribers per channel in 1999: 1000. Average subscribers per channel now: 250. You can do the math from there. Good point, and that trend will continue and get smaller and smaller over time.
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JL
Comcast | |
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