Leave it to the phone companies to make simple ideas complex

Thursday, March 18, 2021

These telephone DNS records are typically expected to contain a record with the type NAPTR. NAPTR, generally speaking, is intended to map addresses (more properly URNs) to other types of addresses. For example, E.164 to SIP. So the NAPTR record, typically, would provide an address type of E2U+sip which indicates ENUM (E.164 number mapping) to the SIP protocol.

Fascinatingly, the actual payload of an NAPTR record is… a regular expression. The regular expression specifies a transformation (with capture groups and the whole nine yards) from the original address (the E.164 number) to the new address type. In theory, this allows optimization of NAPTR records at higher levels of the hierarchy if components of the original address are also used in the new address. This is one of many areas of DNS that are trying perhaps too hard to be clever.

Computers Are Bad: can I get your number domain

I'm very surprised I haven't mentioned NAPTR records before, because I have to deal with them at The Corporation. The service we provide to our customers, the Oligarchic Cell Phone Companies, is to translate a phone number, such as “867-5309” to “Jenny,” and that is done via DNS using NAPTR records. I was surprised at first, because I was expecting the Oligarchic Cell Phone Companies to use some esoteric and proprietary protocol to handle such information, but nope—it's via DNS. One complication here is that each phone company keeps its own database of numbers to names, and you have to negotiate with, and more importantly, pay, each one to query their data. Now, because The Corporation has all these contracts in place, all an Oligarchic Cell Phone Company has to do is pay us to get access to the name databases of the other Oligarchic Cell Phone Companies.

A classic middleman situation here.

But getting back to the article. The author uses the example +18002662278 as an example of an E.164 global number (where E.164 is a standard from ITU), but the example is a bad one, because 800 numbers are not global numbers! You can only dial 800 numbers from North America, so to present +18002662278 as a global number is incorrect. This is an issue for us, because Project: Sippy-Cup has to deal with both global and “local” numbers (where “local” means—intra-country code calling). and yes, we get a ton of 800 numbers sent in as global numbers (then again, we get an amazing assortment of garbage numbers from the Oligarchic Cell Phone Companies, including all zeros, all ones, numbers with international dialing prefixes, short codes, service codes, and it wouldn't surprise me if we get ZIP codes from time to time—you'd think the Oligarchic Cell Phone Companies would filter out such garbage, but hey, they're the Oligarchic Cell Phone Companies, they don't have to care).

I also agree with the author about the use of regular expressions in the NAPTR record. It complicates the spec and in the decade I've been working at The Corporation, I've yet to see anyone use the regular expression transformation, and in the source code parse NAPTR records is this comment from the original developer: “Skip the insanely stupid regexp pattern; we are ignoring it.”

The name lookups are not using the “E2U+sip” addressing, but “E2U+pstndata:cnam” addressing, based off a draft standard from twelve years ago. And reading that specification is a hoot in the light of the harsh reality of … um … reality. It defines the pstndata: scheme as:

pstndatauri  = "pstndata:" datatype ["/" telephone-
subscriber ] ";" content
datatype     = "cnam"
             ; Other datatypes can be defined by adding
             ; alternative values.
content      = [ mediatype ] [ ":base64" ] "," data
mediatype    = [ type "/" subtype ] *( ";" parameter )
data         = *urlchar
parameter    = attribute "=" value

where "telephone-subscriber" is imported from RFC 3966
[19], "urlchar" is imported from RFC 2396 [20], and
"attribute" and "value" are imported from RFC 2045 [21].

LIES! ALL LIES!

Okay, it's not quite that bad, but having dealt with all three RFCs mentioned, I'm not sure the author of the specification carefully read the them, or considered deeply how they might interact. The definition of telephone-subscriber contains not only the “phone number” but also parameters separated by semicolons! I have code to parse telephone-subscriber but I can't use it here because in reality, it conflicts with this definition (why yes, the whole notion of parsing this data came up recently at work, why do you ask?) It's always fun when reality trumps theory (no, not really).

So as the author states, “DNS does handle phone numbers!” But it's not quite as simple as IP addresses.

Wednesday, March 17, 2021

Is there a reason for an indulgence of lepcrechauns on the front lawn? And who replaced the grass with clover?

I'm in the Computer Room. Bunny is in the family room watching TV. I suddenly hear a tune that sounds eerily familiar—I know this music! It's from a TV show, but I can't remember which one. I rush out, only to find it's a commercial using the music.

Darn!

But it's so familiar! I grab my phone and fire up Shazam. “Excuse me,” I say, as I grab the remote from Bunny to rewind and watch the commercial over again. Shazam listens, and then says “Dave Allen At Large.”

That's it!

Dave Allen was an Irish commedian and my friend Bill and I would watch his TV show when we were in high school. I haven't thought about him or his TV show in years! And yet for some odd reason, I was reminded of him today.

I wonder if it has anything to do with the lepcrehauns on the lawn?

Oh, I've got to go—dinner is ready, corned beef and cabbage—wait a minute …

Thursday, March 11, 2021

Place your bets!

I just checked my Gmail account and I received an update on the Mt. Pfeiffer situation five days ago—apparently it is still melting so I guess there's still time to place a bet as to when it will ment completely away.

There's also about 50 recipients to that email, and I'm wondering if I'm supposed to be related to the other four Conner's who received this email. I supposed I should notify the sender, especially given this disclaimer at the bottom of the email:

This message is intended only for the use of the addressee(s) and may contain information that is PRIVILEGED and CONFIDENTIAL. If you are not the intended recipient(s), you are hereby notified that any dissemination of this communication is strictly prohibited.

If you have received this communication in error, please erase all copies of the message and its attachments and notify us immediately.

Your email address and contact information will be stored within XXX's Customer Relationship Management platforms (CRM) and Communication Management Systems and may be used by XXX for lawful business purposes. XXX does not share or sell your contact information. Details about how we use your information and your rights are contained within our Privacy Policy (click here to view our Privacy Policy).

But if I notify the sender of their mistake, I won't get closure! I'm now emotionally attached to Mt. Pfeiffer's fate! Oh the dilemma!

Wednesday, March 10, 2021

Notes on an overheard conversation while passing by a building

“Oh! That building is so hideous! It's … what? Monstrous?”

“Brutalist.”

“That's it! Brutalism!”

“But it's not quite Brutalism.”

“No, this building has windows.”

Tuesday, March 09, 2021

Christmas in March—The Clockwork Gift

On Christmas, one of the gifts I received from Bunny was a small flat box, about 7″ by 7″ and an inch thick—perhaps a CD, but it was no CD. No, there was a small grey pouch with a clock winding key, and two pictures of a grandfather clock (technically, a “grandmother clock” as it's not quite 6′ (2m) in height; both are a type of “longcase clock”).

“It's currently being restored,” said Bunny. “So sorry it's not here in person.”

“Wow!” I said. “It looks just like the one I had as a kid!” Yes, it's true. I was the only kid I knew in high school with a longcase clock in their room. It belonged to my maternal grandparents. When my grandfather died and my grandmother moved in, the clock came with her. My Mom wasn't all that keen on clock, what with all the constant ticking. I, on the other hand, loved it. I did not mind the ticking at all (and that probably explains why I don't mind using the IBM Model M keyboard).

After my Mom died, my uncle (Mom's brother) came down to help move his mother to live with him, and he ended up taking the clock as well. Sigh.

Bunny knows I have a thing for grandfather clocks, as I tend to fawn over them when we're antique window shopping. So it's wonderful that she decided to get me one for Christmas, even though it wasn't here on Christmas.

Josef & Joseph certainly took their time with the restoration, but they wanted to make sure not only it worked, but it worked flawlessly! It finally arrived at Chez Boca today.

[A grandmother clock from Colonial Mfc. Co.] I'll take this tick tock over TikTok any day.

Oh, there were plenty of logistics in getting it home. And way more in getting it set up, spending way over an hour getting various shims under the feet of the clock to get it level. It turns out that even out by 1° from true will eventually bring the pendulum to a stop, and the chimes won't always strike true.

So now it's quietly ticking away (and it's not nearly as loud as one would expect), keeping time quite nicely. It's a nice feeling to know I'll have a time-keeping piece that will survive the next Carrington Event.

Wednesday, February 24, 2021

4

I have a Gmail account that I don't use for anything other than

having claimed seanconner@gmail.com as an email address;
seeing what spam Google lets through its famed “spam filtering process” (hint: quite a bit actually, and I suspect Google gets paid to deliver it);
seeing email for other Sean Conners who's friends/family don't know that seanconner@gmail.com doesn't go to the Sean Conner they know.

That last category is just a by-product of getting in early enough with Gmail, and after all this time, I'm still surprised at receiving email addressed to other Sean Conners (latest one: a betting pool to see when a pile of snow known as “Mt. Pfeiffer” will melt completely away).

So I load Gmail today and get:

We’re sorry, but your account is temporarily unavailable. We apologize for the inconvenience and suggest trying again in a few minutes. You can view the Google Workspace Status Dashboard for the current status of the service.

If the issue persists, please visit the Help Center »

Try Again Sign Out

Show Detailed Technical Info

And when I clicked on “Show Detailed Technical Info” I got “Numeric Code: 4”.

Woo hoo!

Way to go, Google! Wonderful technical detail! That helped a lot!

Monday, February 22, 2021

Lightsabers and Pitfall!

My hetero life mate Hoade finally got around to mailing my ~~Christmas~~ ~~birthday~~ Valentine's Day gift, and I must say, much fun. The first item in the package was the Activision Flashback Blast gaming system, an Atari 2600 in a modern game controller (technically, the games are stored in the HDMI interface that the game controller connects to), and of the twenty games included, I've only heard of half of them, the standout one being Pitfall! The one standout game I never heard of (and by “standout” I mean “WTF was Activision thinking?”) is Crackpots, a kind of reverse Space Invaders, but instead of bug-eyed aliens marching down towards you, it's actual bugs crawling up towards you. Interesting take on the genre, but still a WTF moment the first time I played it.

In fact, not having instructions makes these game all the more fun. Back in high school and through college, my friend Bill and I would often … um … aquire … games and attempt to play them without knowing how to play. I still recall playing Barbarian: The Ultimate Warrior with Bill and both of us falling over laughing when suddenly and rather unexpectedly, one of us somehow managed to chop the head off the other player.

The other gift Hoade sent was a “Lightsaber™ Ice Pop Maker.” A kit of four small lightsabers (two modelled after Darth Vader's saber, and two moddeled after Luke Skywalker's second, green lightsaber) and a mold to make four pops at a time.

[My hand, holding up a Darth Vader Lightsaber™ Ice Pop that isn't quite lit up all the way] “I find your lack of lightsaber … disturbing!”

As a test, we used cranberry juice for two of them (one for Darth's, one for Luke's—just to see how the green LED interacts with the red cranberry juice) and ginger ale for the other two. I'm not sure if we left them in the freezer long enough, because the first two I attemped to pull out broke apart. The third one came out (after running hot water over the mold) but Bunny and I learned that we should have used flat ginger ale—the carbonation caused large pits in the “light” portion of the lightsaber. And as you can see in the image above, the light doesn't quite go all the way through.

We have ideas for other attempts.

Anyway, I want to thank Hoade for the gifts. They were much appreciated and caused some great merriment here in Chez Boca.

The Boston Diaries

Thursday, March 18, 2021