Truth in Broadband

OK, fellow nerds, you can tune back into the discussion now. This post features a good explanation from the head of Cloud Alliance, a wireless ISP (WISP) in central Vermont, of what happens in the network of a provider when total demand from users exceeds the size of the connection available from that network to the broader Internet . After that, I expound on truth in bandwidth reporting.

Quoth Michael Birnbaum in a comment on a broadband primer post:

“Assuming that we were to purchase sufficient digital bandwidth from our supplier to handle the heaviest traffic, subscribers would receive the advertised maximum throughput, all the time. This is the "maximum information rate."[nb. Henceforth “mir”] We don't purchase that much capacity, of course, because much of it would lie unused, most of the time like a 64 lane highway. So, the "committed information rate" [nb. henceforth “cir”] kicks in when the total traffic exceeds a preset limit. Cir settings are not usually made public, but I can say they are typically less than half of those of the mir (which are the typical advertised maximum rates). This knocks in to be fair to everyone, so that no individual users get to be hogs to the others' detriment. If we have purchased a reasonable amount of digital bandwidth, the cir only kicks in for short bursts, and the subscribers return to higher throughput again. The subscribers do get to see the advertised mir but only occasionally, during the busy parts of the day. The rest of the time they are sharing at a slower rate, but not as slow as that which causes the cir to kick in. During the quiet parts, they get full speed.”

Many ISPs use techniques like this to distribute the pain when there is more demand for Internet connectivity than can be instantly satisfied. Some, I suspect, use techniques much more pernicious but that’s another post for another day. Few ISPs are as forthcoming as Michael in explaining what they do and why they do it.

It would be unrealistic (and incredibly expensive) to require ISPs to deliver the full mir all of the time. Michael’s analogy of a 64 lane highway is a good one – might be handy once in the while but most of the time is a terrible waste. But, as Michael points out, most ISPs don’t advertise their cir nor reveal how often they need to throttle users back to this speed. It is also true that, if the total demand is high enough, the ISP may not be able to deliver the “committed” information rate (cir) to all customers either.

The biggest problem, it seems to me, is that you have no idea what to expect when an ISP tells you the maximum information rate (mir) only. If the cir is a significant portion of this – say half – and if the cir is in effect only during peak hours and occasional traffic jams and if the ISP really can deliver at least the cir 95% of the time, then most of us would probably be happy most of the time with service from that ISP. That last is not a very definitive sentence.

It’s possible that, if the US had a more competitive market for Internet access, anecdotes from friends about their subjective experience would be enough to help us judge whether  a particular ISP delivered a sufficient fraction of the mir a sufficient portion of the time. Only in a competitive market where we have more than one choice could we use that information to make an informed choice of providers. Only in a competitive market would ISPs feel the pressure to advertise the numbers under the numbers and live up to them.

Since we don’t have very competitive market for broadband access in most of the United States and have no competition at all in other parts, I think some regulation of advertised rates IS appropriate even though regulation is fraught with dangers of its own. I’ll make some suggestions soon. Suggestions for regulation are here.