This is funny. About 10 years ago, I had bonded ADSL for my internet (yay sonic.net). The idea being that two lines bonded together would have twice as much bandwidth as a single line. Each line had a max rate of 20Mbps, so I had a max of 40Mbps combined. It worked pretty well initially, but over time it degraded horribly. Because you could see stats for each line independently, I could tell that one line was operating at ~18Mbps and the other was around 2 and there was a lot of error recovery going on. After much complaining, I found out that one line was degraded and somehow reacted to rain (water got in the trunk somehow). And no, AT&T wasn’t going to fix the broken line.
I chose to just use the single (good) line.
So, yes, I can confirm this does work in the field… but with about as much practically as you’d expect.
Another issue with DSL bonding is crosstalk, which is pretty bad in many cases of telco wiring.
10 years ago there was a huge amount of surplus Cisco 1700s with SHDSL line cards (apparently coming from Czech government's project to connect every school to internet in early 00's) and we had huge spool of flat phone cable that was left over from earlier project. So we had the bright idea to wrap ethernet trafic in AAL5, pass that over SHDSL and use that as an LAN for anime convention. Interesting observation from that it matters whether the cable is coiled or un-coiled. We built and tested the whole network in a lab (with coiled cables), it worked well, the G.991bis bonded links synced up at 6Mbps with two pairs and everything was good. We labeled everything and we built the exact same thing (including same cables) at the venue and the links will not go above 1.5Mbps and were frequently losing sync. Disabling the second bonded pair caused it to work reliably at 2Mbps. (Back then, we did not need that much of bandwidth, it was essentially for few SCCP phones, some IP tunelled serial ports and ssh)
Well, next year we bought two boxes of Cat5 cable and switched to native ethernet (and today the backbone spans are 10G fiber, as it also carries video streams).
Ah yeah, if it was just flat cable instead of twisted pair or coax, coiling the cable could have made a massive difference in the characteristics. Interesting that coiling worked better...
I’m always a bit amazed when every home has 2 lines running to it, and probably 99% of those second lines never get used, but telcos figured it was worth it for those occasional 2nd lines/fax lines or redundancy instead of ever needing to run a 2nd pull.
Is this just a North America thing or an everywhere thing?
Only two? Around 1995 we had four phone lines: home, home office, fax, and modem. There were only three physical pairs, so two of the lines (I think the voice lines) came off one physical pair with a frequency division splitter.
Some time later I saw a Pacific Bell truck and crew trenching the street. (We had underground utilities.) I excitedly asked them, "Are you running fiber?" "No, just more copper."
I guess they saw the demand for lots of copper lines per house and decided to meet it!
The underground phone lines did lead to some excitement one time. Their water sealing wasn't very good, and after a heavy rain the line would get noisy and clicky. During one of these episodes, we got a loud knock on the door: "San Jose Police! Open up!"
I ran to the door and asked what was going on. One of the officers said, "We got a 911 call from this address. The dispatcher couldn't hear anyone on the line, and no one answered when they called back. So we're required to come out and investigate the situation."
I replied, "That's odd, neither of us called 911. Oh... I think I know what may have happened. Come in and I'll show you."
We went to the kitchen and I put the wall phone (remember those?) on speaker and had the officers listen. It was clicking up a storm!
Then I asked them if they remembered the old rotary phones (they did). I explained how the phone dial worked by breaking and making the circuit N times for each digit you were dialing. And it must have been that in that flurry of clicks that the circuit was broken nine times, then once, then once again.
In India it was pretty common for phones put in semi-public locations to have a lock on the dial to stop people making outgoing calls. But if you were motivated enough, you could still dial out by tapping the number out on the switch hook.
> Some time later I saw a Pacific Bell truck and crew trenching the street. (We had underground utilities.) I excitedly asked them, "Are you running fiber?" "No, just more copper."
During the Australian NBN^^ rollout. Where I used to live was on the border of a FTTC and a coax/DOCSIS one. My street had no pre-existing cable TV cable so you'd think no brainer to lay fibre. Nope, brand new coax. And because the street had no coax that meant no homes had an existing cable so they had to trench every driveway to connect it to the street. It would have been an absolute no brainer to run fibre then use the existing phone lines up driveways to their homes. Cheaper, and an easy upgrade path to full fibre. This was 2019.
^^Australia built a national broadband network. It was originally designed to be all fibre (except for remote places over satellite etc), but politics happened and it was changed to a multi technology mix which included DOCSIS, fibre to the node then vdsl for the last km or whatever, or fibre to the curb and vdsl up your driveway. And the government entity building it NBN was buying up old copper phone lines and coax.
In Germany, the government of Helmut Schmidt (social democrats) planned to implement an optical network to every house in west Germany in 1981. In 1982 Helmut Kohl became chancellor, cancelled the 30 year plan and what we got was coax lines for cable TV. Thanks a lot, just imagine where Germany could be today … to be fair, a significant part of households gets their internet connection over the cable tv networks, but still it was a dumb decision.
Don‘t forget that Helmut Kohl was also sharing a bed with the television industry at that time when optical networks couldn’t transmit analogue television.
Standard neoliberal bullshit coupled with a lack of imagination as to how things like local-loop unbundling might be used to create a competitive market. The UK is now in a fairly good position re broadband, but it could be so much better.
If you go everywhere, you'll rapidly find countries where landlines didn't get meaningful penetration outside of metropolita areas at all.
But even in North America, I don't think every home had two pair all the way to the central office. They might not even all have two pair all the way to the crossbox [1]. It was not uncommon to order a 2nd phone line, and not be able to get it, because there weren't any available pairs on your pole. Especially if your neighborhood was established well before the explosion of the internet and fax in the mid to late 90s.
Very common across Europe too. Makes sense, running a second line is so much labour that only a few would have to order it to make the extra cable cost for everyone worth it.
It's also all the wiring in the walls, too. They all carry two lines, and you could even buy "two line telephones."
It made a lot of sense when I ran a dial-up BBS, or for homes that were heavy modem users. Otherwise, once high-speed internet was an option, 2nd lines made less and less sense.
We had a serious degradation in line speed every time it rained. We rang our isp (Andrews and Arnold, the same as in the original post), and it was fixed in a week. Thanks A&A!
I think the secret is that they are small enough to be a constant hassling nuisance, so OR now knows that they’ll just get grief until it’s done. Squeaky wheel and all that :)
I chose to just use the single (good) line.
So, yes, I can confirm this does work in the field… but with about as much practically as you’d expect.