Recently there’s been a flurry of discussions about bandwidth shortages, not to mention bandwidth hogs, bandwidth caps, network neutrality and what constitutes fair practices by ISPs. But there is very little public data and no transparency!
So let me offer a (very) few actual data points, one from a few years ago and three fairly current. These come from friends who are operators and from emails shared on trade association mail lists. Since some of it was not intended for publication, I have withheld specific names.
Notice contention ratios vary widely and yet each of these operators has enough extra capacity that they claim to avoid link saturation and its impacts, like packet loss and excessive ping times. It’s true these are all small operators (280-1200 customers) so this data lacks the statistical smoothness one would expect when aggregating traffic from thousands or millions of subscribers.
I also have some data on traffic averages by time and by number of subscribers that I’ll share in a subsequent blog post.
Mar 2006 – Rural ISP (Dialup, DSL & Wireless)
130 Motorola Canopy subscribers (with 512 Kbps service)
150 DSL subscribers (110 with 512 Kbps service; 40 at 1 Mbps)
100 dialup lines serving 800 customers (average 40 Kbps)
Daily traffic was saturating 4.5 Mbps (3 T1s) for an hour per day but not with 6 Mbps.
Contention ratio: 164Mbps / 6 Mbps -> 27:1
Traffic per BB user: 6 Mbps / 280 subscribers -> 21 Kbps
Sep 2009 – Rural ISP (DSL & Wireless)
1200 customers, DSL subs at 1.5, 3 or 6 Mbps; wireless subs at 384 Kbps, 768 Kbps, 1 Mbps or 3 Mbps. I don’t have the mix, so I'm guessing the contention ratio.
Daily traffic peaks at around 35-40 Mbps; up to 150 Mbps Internet transit available.
Contention ratio: 2400 Mbps(?) / 150 Mbps -> 16:1
Traffic per BB user: 40 Mbps / 1200 subscribers -> 33 Kbps
Sep 2009 – Community-run WISP
340 customers, mostly on 3-4 Mbps service
Daily traffic peaks around 17 Mbps; 45 Mbps of Internet transit available.
Contention ratio: 1190 Mbps / 45 Mbps -> 26:1
Traffic per BB user: 17 Mbps / 340 members -> 50 Kbps
Sep 2009 – Rural ISP
370 customers: 300 Customers on wireless (1-3 Mbps) and 70 customers with FTTH (10/100 & up, but most have 10 Mbps peak). Monthly fees based on a 10 or 20 GB cap with extra charges for heavier use.
Daily traffic peaks at 13-14 Mbps; 20 Mbps of Internet transit available.
Contention ratio: 1200 Mbps (?) / 20 Mbps -> 60:1
Traffic per BB user: 14 Mbps / 370 subscribers -> 37 Kbps