diego's weblog

there and back again

Monthly Archives: January 2011

too bad phone number records don’t have a TTL

It’s been almost a day since I ported my phone number from AT&T to Google Voice, and I still can’t receive SMS or international calls. Mind you, the porting process explicitly stated that SMS could take up to three days to transfer over, but while I was doing it I didn’t pay much attention to that.

Yesterday, when someone was trying to call me from abroad and got “this number has been disconnected” as a response, the obvious struck me: phone numbers, like DNS, clearly has a set of local caches at your local endpoint that know who is responsible for that phone number and lets it figure out the rounting. When the owner of the record changes the changes must propagate world-wide, and this takes time. Caching policies must vary between providers, and given how rarely phone numbers change, it’s reasonable that the cache would be fairly long-lived. SMS and international calls must both use the same name-resolution (or number-resolution) routing system.

As I said, fairly obvious, but it’s one of those things that we rarely think about. I’ve been searching online for a bit on information on these systems but can’t seem to find any. I’m curious about the protocol they use, and how much like (or unlike) DNS it may be. My bet is that with the benefit of hindsight it’s an arcane, bizarre system, evolved painfully and slowly over a long time that everyone would like to change, but can’t. Oh, wait, that is DNS.

Either that, or there’s a giant building somewhere with rows of filing cabinets disappearing into the distance, with grim-looking people pushing carts full of punchcards that have to be moved from one filing cabinet to another. I’ll keep looking and see which one it is.

“because your computer is too fast”

La Brea: a really interesting tool that uses “AOP-style” cross-cutting wrappers for OS-level calls. I am generally obsessed with the idea that we trust too much the underlying systems that we run software on, and this shows in many subtle ways in code as we are writing it, particularly around error detection, correction, and reporting. “Try La Brea” definitely goes in the to-do list.

bye bye, AT&T

On Wednesday the story broke that Google was testing number porting for Voice, but I got there too late: the option was already gone by the time I checked. Then yesterday it occurred to me to check again, and lo and behold, there it was.

It just so happened that I was angrier at AT&T than usual (thanks to some ridiculous charges on an international call made by mistake) and since I’ve been doing mobile development recently I need to shift between Android and iOS devices more frequently (Blackberry is a maybe at this point). Google Voice is the perfect solution for that. I didn’t hesitate to start the process.

Not-long-story-short: porting initiated yesterday, completed almost exactly 24 hours after (still waiting for SMS to come back on) without me having to do anything more than going through a few simple screens on the Google Voice site and paying $20. For the moment routing my calls to a Verizon HTC incredible and using the iPhone 4 for everything I used it before, since it couldn’t really make calls anyway, the main advantage of AT&T was the data connection. So WiFi or the mobile hotspot feature on Android will do when “regular” WiFi isn’t available, and I might end up getting a Verizon iPhone anyway to see how the interaction between app usage (data) and voice, notifications, etc, is handled.

No doubt AT&T is going to slap me with a hefty ETF, but after years of poor service (which was improving slightly in recent months, but only slightly), dropped calls, missed calls, etc., I had enough. I may end up using an AT&T device at some point for a brief period, but for now, I am AT&T-less. At last!

two articles

and two quotes.

1) “How much time do you spend verbalizing?  Every time you talk, you destroy the memory of what you’re talking about.” from Science Proves You’re Stupid

2) “Is [the software we use] it really fulfilling our needs? Or are we reducing the needs we feel in order to convince ourselves that the software isn’t limited?” from Generation Why?

Both good reads. Recommended.


First off: happy new year!

The post title was too much to resist, honestly, which clearly says something about how my brain works. I’ll be damned if I know what it is that it says though.

While I was musing about writing something it occurred to me that an arbitrary marker to signify that our planet has taken one more turn around the star it is orbiting is not a particularly good occasion given that my posting has been so horribly erratic for, well, years now. Then seeing that the newspapers engaged in their usual new year stories of “photos of the new year” along with the usual “how they received new years in [insert random part of the world that seems exotic mixed in with the familiar]” I amended my thought to: “oh, fuck it.”

And here we are. Except now there isn’t much of a coherent stream of ideas to set down on, um, “paper” (sorry, but I do miss saying that, and it having meaning, for some reason), and rather there’s just a jumble of flashes half-baked notions that I am, quite frankly, too lazy to try to organize at the moment. I won’t bother even with a preview, but suffice it to say that when any list includes both the economics of Near-Earth Asteroid mining and Objective-C… well.


So before I end the randomness by posting this – how about something to read? The Decline Effect and the Scientific Method is one of my favorite articles in recent times. If that’s too dense, try Roomba Violates All Three Laws of Roombotics. Enjoy!


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