16 ms·

All these things are related. Back in the 1990s I worked with others to develop DSL technologies (ADSL, HDSL, VDSL) for telcos. Why not fiber, some ask? oh,

All these things are related. Back in the 1990s I worked with others to develop DSL technologies (ADSL, HDSL, VDSL) for telcos. Why not fiber, some ask? oh, fiber materials may be sand, but installed fiber is sand, energy, and labor. Installation costs trump everything - use what you have for the physical medium. While we (PairGain) also made point-to-point private links, it was clear then, and even moreso now that most DSL involves a service provider managing the network - with specialized skills, practices and setup. In the 2010's I was spending time with the Ethernet folks, and in particular industrial folks with large plants. I ended up chairing IEEE Std 802.3cg which developed the 10 Mb/s 1km technology. Not really a speed increase - more an application refocus. As the networking world developed, many realized that converging networks above the physical layer added network complexity and therefore setup and ongoing operating costs... So we now also have SPE - pure Ethernet at DSL-like distances... Similar tech with different use models, enabling connectivity for whatever... I'm not Al Gore - I won't claim to have invented the internet. I just an engineer who happened to have a hand in both of these technologies, and am still pleased to see that people use them.

yosheli123 4y ago
Awesome to have your input on this. I'd love to talk to you in person to learn more. Reach out at josh@botblox.io
Aloha 4y ago
I remember seeing your guys HDSL hardware in the field what seems like a million years ago. (for those without a telecom background) It was pretty common as a way to extend T1's without conditioned lines or repeaters then. Interestingly enough, I'd done direct t-spans's inside of a building over house cable in a situation that was too long (and too poor of cable) to do Ethernet.
throwaway____10 4y ago
What a blast from the past, DSL was an exciting technology. I did the config and networking of DSLAMs for the first private test installs of Paradyne (Hotwire) DSL hardware in a western state around ~1998-1999, a couple years before DSL really hit the mainstream. The telecos were slow to move on the technology and didn't do their own centralized rollouts until several years later. We took full advantage of that lead time time to win away a lot of ISDN customers with much lower prices and much faster service. We also saw end of that advantage coming and got out of the business before we had to compete directly with the telecos who could operate at scale and do bundled pricing of the line + service that was harder to compete with. At the time high speed internet over cable was also a while off for the general public. We also had a tip from a teleco employee that we could use DC Signalling channels / dry copper pairs instead of regular phone circuits (no dial tone, they were meant for alarm service). They cost about 1/2 to 1/3 of the price. At one point we petitioned to get the local telco to dig up the sidewalk and install several hundred more copper pairs into the building. It was really interesting to watch the internet access landscape change so quickly.
oasisbob 4y ago
> While we (PairGain) also made point-to-point private links, it was clear then, and even moreso now that most DSL involves a service provider managing the network - with specialized skills, practices and setup. Mmm. This brings back memories of running private DSLAMs in a campus environment as a transitional pre-Ethernet stopgap in the early 2000s. 95% of the DSL lines worked great. The remaining 5% were a never-ending nightmare of troubleshooting and sudden breakage. We didn't want to be DSL experts, we just wanted the hardware to work well-enough for long enough to make it all go away.
- jleahy 4y ago
  I actually ran a private DSLAM to get internet between upstairs and downstairs in my house only a few years ago (not a joke, G.fast).
mbarras_ing 4y ago
Dr Z! I've recently started at Tunstall Healthcare and you are frequently referenced when refering to SPE. I'm the first person they've had working full time on SPE, so hoping to make some progress :)
bsder 4y ago
This is nice, but how long is it going to take until we get multi-drop over single pair back? You know ... a technology that we could do back in 1986? It seems like 10baseT1-S is never going to actually come out.
cm2187 4y ago
Fiber doesn’t conduct electricity, a wire does. I remember reading somewhere to be careful with running a wire over any long distance between two houses that are not connected to the grid with the same meter. Something to do with phase or different potential, can’t remember, but the point was it could fry your equipment. Fiber sounds a lot safer to me.
- dekhn 4y ago
  Any long run like this would use optoisolaters.
- midasuni 4y ago
  The biggest problem is lightning strikes hitting the cable. The phase wouldn’t matter - and even different earthing wouldn’t matter as long as you only connect any shield at one end. But fibre is so much more versatile if you’re running new cables (unless you want to run power)
  - repiret 4y ago
    Last summer the local cable company replaced all their cables in town in order to begin offering digital cable and internet service. I was flabbergasted that they they spent all that money on linemen but still ran coax rather than fiber. As far as I can tell talking to their linemen, its not even FTTN, just FTT-central-office. Assuming its not run by morons, which I'll accept is a bit of a stretch for a cable company, there must be some other reason to not run fiber for new installations.
    - jcrawfordor 4y ago
      DOCSIS is capable of 3gbps over coaxial cable and there is more room to improve, so fiber doesn't have a significant advantage in terms of possible bandwidth. Because DOCSIS was designed to operate on the cable network, which was designed to reach a very large number of homes, the architecture of the system tends to be more cost-effective than fiber. The fiber equivalent of a cable-like topology, and what is used by fiber ISPs, is PON, but PON is actually relatively limited in terms of both range and number of service points compared to DOCSIS on cable. A typical PON installation requires more field equipment to serve the same customers at the same rate compared to DOCSIS. This is made worse by the issue of power distribution: the field equipment for DOCSIS consists of distribution amplifiers which are powered over the coaxial cable itself, allowing the battery-backed power supplies to be placed at convenient locations. There's not really any equivalent of this for PON, so extending PON networks beyond a single loop (depends a lot but typically a few KM and <100 customers) requires an OLT which is relatively large and needs separate power provisioned. You can put OLTs in serving area cabinets but this is costlier compared to cable equipment. Another major factor is the customer premises: most homes already have coaxial cable distribution installed that is either compatible with DOCSIS 3 or can be made compatible with DOCSIS 3 by replacing the distribution amplifier or passive tap, which is a fairly cheap and fast operation. Installing PON to customers requires getting fiber to their house, and then either an outdoor ONT (troublesome from a maintenance perspective) and ethernet into the building or fiber into the building. The equipment here doesn't necessarily cost much but the labor of running new lines into customer homes is substantial and makes signing up new customers much higher-friction. Most of the time when a cable provider upgrades to introduce DOCSIS 3 for digital voice and internet they aren't really replacing any cable anyway, just distribution amplifiers and nodes. The cost of this work is significantly lower than running new cable and it doesn't require new pole attachment agreements etc. In general, in urban environments with existing cable TV plant there are few upsides to fiber. Urban fiber in existing areas is usually only cost effective when it's a new ISP competing with the cable company. Finally, most DOCSIS networks are in a process of transitioning from CMTS (cable modem termination system, the upstream end) in the cable headend to a compact serving area CMTS at each amplifier point. This is called "Node+0" architecture, meaning there is a fiber node and then zero distribution amplifiers before the customer. One of the nice things about the cable "HFC" or hybrid fiber/coaxial network is that it is relatively easy to make this transition progressively as you sign up additional customers, since CMTS nodes have been made very small. PON is less forgiving this way and requires more up-front capacity planning, especially since network expansion means the permitting process on relatively large curb cabinets or enclosures.
netsharc 4y ago
Al Gore never claimed that, btw, but he did recognize its importance and provided political support, even Vint Cerf said so: https://www.snopes.com/fact-check/internet-of-lies/ https://www.snopes.com/fact-check/internet-of-lies/
- dekhn 4y ago
  there is an entire multiverse fan fic where Al Gore won the presidential election and we're all living in a post-scarcity society.
  - JohnJamesRambo 4y ago
    I want to live there. My jar of mayo costed $5.50 with tax yesterday.
- Xeoncross 4y ago
  "During my service in the United States Congress, I took the initiative in creating the Internet" Sounds like we're playing word games at this point. Imagine that, a politician playing word games.
- serf 4y ago
  >Al Gore never claimed that, btw, GORE: “During my service in the United States Congress, I took the initiative in creating the Internet. I took the initiative in moving forward a whole range of initiatives that have proven to be important to our country’s economic growth and environmental protection, improvements in our educational system.” There are three ways to read the first sentence, two of which take the presumption that Al Gore invented the internet. Snopes is so half-wrong that it's getting to be easy to ignore. In other words , he did say that, he just didn't mean for people to interpret his ambiguous statement in that fashion. aside : the word of the day is initiative.
  - zuminator 4y ago
    Gore absolutely deserves to be dinged for speaking ambiguously in a way that leans towards greatly inflating his contribution to the field. But at the same time, anyone who's ever read or written a résumé will readily recognize "took the initiative in creating" as CV-speak for "I assisted in some capacity, however minor." I expect the actual number of people misled by Gore's self-puffery to have been small to nonexistent.
kombre 4y ago
>oh, fiber materials may be sand what does sand means in this context please ?
- hervature 4y ago
  Fiber optics cables are made of glass whose primary constituent is silicon dioxide and/or quartz which are the primary constituents of sand.
  - kombre 4y ago
    oh okay, thx
  - NegativeLatency 4y ago
    And therefore should be cheap in a naive estimate
    - jaredhallen 4y ago
      To be fair, fiber cable itself is actually pretty cheap in the scheme of things. It's the installation and termination that account for the bulk of the cost
tomhoward 4y ago
Cool to see you here on HN. I hadn't heard the name PairGain since I worked for a small corporate ISP in the early 2000s. We'd recommend PairGain modems for clients who needed seriously high-speed links of 2Mbps! This was just before ADSL and SHDSL were rolled out en masse, or at least well before they were reliable enough for corporate use. We had to organise a special installation of a direct copper line from their premises to ours. I guess they just patched them together at the exchange? It was a pretty small catchment area. Fun times!
- EvanAnderson 4y ago
  The tariff in my locality allowed for dry copper pairs to be installed ("burglar alarm circuits") and some of my Customers took advantage of that along w/ PairGain devices to get high speed links between sites serviced out of the same central office. Relevant article: http://helices.org/commentary/dry_copper_pair.html http://helices.org/commentary/dry_copper_pair.html
  - watersb 4y ago
    I can't tell exactly from a quick scan of Cringeley's commentary... but I get the impression that a "dry copper pair" the single-pair POTS equivalent of "dark fiber"... with the critical caveat that a dry copper pair can link two points only if they are serviced by the same central telephone company switch.
    - jcrawfordor 4y ago
      A leased loop is any arrangement where a customer pays the telco for a dedicated loop for continuous use. A dry loop is a type of leased loop that isn't connected to any telco equipment, just spliced together to create a continuous circuit (a typical or 'wet' leased loop has at least battery and sometimes dial tone from the telephone switch). It's perfectly possible to get a leased line that spans telco offices, in which case your loop has to be spliced to an interoffice or toll lead (long distance line). In the days before heavy use of multiplexing, toll leads were scarce and so interoffice leased lines were extremely expensive. Dry loops were often sold as burglar alarm circuits because one of the most common uses was for burglar alarm communicators that often operated on polarity reversal - meaning that they applied a potential to the pair and just swapped its polarity when an alarm condition occurred. Of course there were more sophisticated burglar alarm communicators at the time that used telegraphy techniques, but these usually ran on private networks since they could share a bus in a way that was not typical of telco infrastructure (most of these were basically Gamewell systems even if not made by Gamewell proper). In the early days of burglar alarm monitoring, if the monitoring service didn't have a private network (typical in urban areas) they usually installed their monitoring equipment or a multiplexing system at each telephone exchange in the covered area, allowing for more economical dry loops within a single office. Actually this pattern continued well into the '90s with some burglar alarm services using DSL-like high-frequency digital communicators that interacted with a monitoring system that had to be connected to the line card at the telephone exchange.

yosheli123 4y ago

Awesome to have your input on this. I'd love to talk to you in person to learn more. Reach out at josh@botblox.io

Aloha 4y ago

I remember seeing your guys HDSL hardware in the field what seems like a million years ago. (for those without a telecom background) It was pretty common as a way to extend T1's without conditioned lines or repeaters then. Interestingly enough, I'd done direct t-spans's inside of a building over house cable in a situation that was too long (and too poor of cable) to do Ethernet.

throwaway____10 4y ago

What a blast from the past, DSL was an exciting technology. I did the config and networking of DSLAMs for the first private test installs of Paradyne (Hotwire) DSL hardware in a western state around ~1998-1999, a couple years before DSL really hit the mainstream. The telecos were slow to move on the technology and didn't do their own centralized rollouts until several years later. We took full advantage of that lead time time to win away a lot of ISDN customers with much lower prices and much faster service. We also saw end of that advantage coming and got out of the business before we had to compete directly with the telecos who could operate at scale and do bundled pricing of the line + service that was harder to compete with. At the time high speed internet over cable was also a while off for the general public. We also had a tip from a teleco employee that we could use DC Signalling channels / dry copper pairs instead of regular phone circuits (no dial tone, they were meant for alarm service). They cost about 1/2 to 1/3 of the price. At one point we petitioned to get the local telco to dig up the sidewalk and install several hundred more copper pairs into the building. It was really interesting to watch the internet access landscape change so quickly.

oasisbob 4y ago

> While we (PairGain) also made point-to-point private links, it was clear then, and even moreso now that most DSL involves a service provider managing the network - with specialized skills, practices and setup. Mmm. This brings back memories of running private DSLAMs in a campus environment as a transitional pre-Ethernet stopgap in the early 2000s. 95% of the DSL lines worked great. The remaining 5% were a never-ending nightmare of troubleshooting and sudden breakage. We didn't want to be DSL experts, we just wanted the hardware to work well-enough for long enough to make it all go away.

jleahy 4y ago
I actually ran a private DSLAM to get internet between upstairs and downstairs in my house only a few years ago (not a joke, G.fast).

mbarras_ing 4y ago

Dr Z! I've recently started at Tunstall Healthcare and you are frequently referenced when refering to SPE. I'm the first person they've had working full time on SPE, so hoping to make some progress :)

bsder 4y ago

This is nice, but how long is it going to take until we get multi-drop over single pair back? You know ... a technology that we could do back in 1986? It seems like 10baseT1-S is never going to actually come out.

cm2187 4y ago

Fiber doesn’t conduct electricity, a wire does. I remember reading somewhere to be careful with running a wire over any long distance between two houses that are not connected to the grid with the same meter. Something to do with phase or different potential, can’t remember, but the point was it could fry your equipment. Fiber sounds a lot safer to me.

dekhn 4y ago
Any long run like this would use optoisolaters.
midasuni 4y ago
The biggest problem is lightning strikes hitting the cable. The phase wouldn’t matter - and even different earthing wouldn’t matter as long as you only connect any shield at one end. But fibre is so much more versatile if you’re running new cables (unless you want to run power)
- repiret 4y ago
  Last summer the local cable company replaced all their cables in town in order to begin offering digital cable and internet service. I was flabbergasted that they they spent all that money on linemen but still ran coax rather than fiber. As far as I can tell talking to their linemen, its not even FTTN, just FTT-central-office. Assuming its not run by morons, which I'll accept is a bit of a stretch for a cable company, there must be some other reason to not run fiber for new installations.
  - jcrawfordor 4y ago
    DOCSIS is capable of 3gbps over coaxial cable and there is more room to improve, so fiber doesn't have a significant advantage in terms of possible bandwidth. Because DOCSIS was designed to operate on the cable network, which was designed to reach a very large number of homes, the architecture of the system tends to be more cost-effective than fiber. The fiber equivalent of a cable-like topology, and what is used by fiber ISPs, is PON, but PON is actually relatively limited in terms of both range and number of service points compared to DOCSIS on cable. A typical PON installation requires more field equipment to serve the same customers at the same rate compared to DOCSIS. This is made worse by the issue of power distribution: the field equipment for DOCSIS consists of distribution amplifiers which are powered over the coaxial cable itself, allowing the battery-backed power supplies to be placed at convenient locations. There's not really any equivalent of this for PON, so extending PON networks beyond a single loop (depends a lot but typically a few KM and <100 customers) requires an OLT which is relatively large and needs separate power provisioned. You can put OLTs in serving area cabinets but this is costlier compared to cable equipment. Another major factor is the customer premises: most homes already have coaxial cable distribution installed that is either compatible with DOCSIS 3 or can be made compatible with DOCSIS 3 by replacing the distribution amplifier or passive tap, which is a fairly cheap and fast operation. Installing PON to customers requires getting fiber to their house, and then either an outdoor ONT (troublesome from a maintenance perspective) and ethernet into the building or fiber into the building. The equipment here doesn't necessarily cost much but the labor of running new lines into customer homes is substantial and makes signing up new customers much higher-friction. Most of the time when a cable provider upgrades to introduce DOCSIS 3 for digital voice and internet they aren't really replacing any cable anyway, just distribution amplifiers and nodes. The cost of this work is significantly lower than running new cable and it doesn't require new pole attachment agreements etc. In general, in urban environments with existing cable TV plant there are few upsides to fiber. Urban fiber in existing areas is usually only cost effective when it's a new ISP competing with the cable company. Finally, most DOCSIS networks are in a process of transitioning from CMTS (cable modem termination system, the upstream end) in the cable headend to a compact serving area CMTS at each amplifier point. This is called "Node+0" architecture, meaning there is a fiber node and then zero distribution amplifiers before the customer. One of the nice things about the cable "HFC" or hybrid fiber/coaxial network is that it is relatively easy to make this transition progressively as you sign up additional customers, since CMTS nodes have been made very small. PON is less forgiving this way and requires more up-front capacity planning, especially since network expansion means the permitting process on relatively large curb cabinets or enclosures.

netsharc 4y ago

Al Gore never claimed that, btw, but he did recognize its importance and provided political support, even Vint Cerf said so: https://www.snopes.com/fact-check/internet-of-lies/ https://www.snopes.com/fact-check/internet-of-lies/

dekhn 4y ago
there is an entire multiverse fan fic where Al Gore won the presidential election and we're all living in a post-scarcity society.
- JohnJamesRambo 4y ago
  I want to live there. My jar of mayo costed $5.50 with tax yesterday.
Xeoncross 4y ago
"During my service in the United States Congress, I took the initiative in creating the Internet" Sounds like we're playing word games at this point. Imagine that, a politician playing word games.
serf 4y ago
>Al Gore never claimed that, btw, GORE: “During my service in the United States Congress, I took the initiative in creating the Internet. I took the initiative in moving forward a whole range of initiatives that have proven to be important to our country’s economic growth and environmental protection, improvements in our educational system.” There are three ways to read the first sentence, two of which take the presumption that Al Gore invented the internet. Snopes is so half-wrong that it's getting to be easy to ignore. In other words , he did say that, he just didn't mean for people to interpret his ambiguous statement in that fashion. aside : the word of the day is initiative.
- zuminator 4y ago
  Gore absolutely deserves to be dinged for speaking ambiguously in a way that leans towards greatly inflating his contribution to the field. But at the same time, anyone who's ever read or written a résumé will readily recognize "took the initiative in creating" as CV-speak for "I assisted in some capacity, however minor." I expect the actual number of people misled by Gore's self-puffery to have been small to nonexistent.

kombre 4y ago

>oh, fiber materials may be sand what does sand means in this context please ?

hervature 4y ago
Fiber optics cables are made of glass whose primary constituent is silicon dioxide and/or quartz which are the primary constituents of sand.
- kombre 4y ago
  oh okay, thx
- NegativeLatency 4y ago
  And therefore should be cheap in a naive estimate
  - jaredhallen 4y ago
    To be fair, fiber cable itself is actually pretty cheap in the scheme of things. It's the installation and termination that account for the bulk of the cost

tomhoward 4y ago

Cool to see you here on HN. I hadn't heard the name PairGain since I worked for a small corporate ISP in the early 2000s. We'd recommend PairGain modems for clients who needed seriously high-speed links of 2Mbps! This was just before ADSL and SHDSL were rolled out en masse, or at least well before they were reliable enough for corporate use. We had to organise a special installation of a direct copper line from their premises to ours. I guess they just patched them together at the exchange? It was a pretty small catchment area. Fun times!

EvanAnderson 4y ago
The tariff in my locality allowed for dry copper pairs to be installed ("burglar alarm circuits") and some of my Customers took advantage of that along w/ PairGain devices to get high speed links between sites serviced out of the same central office. Relevant article: http://helices.org/commentary/dry_copper_pair.html http://helices.org/commentary/dry_copper_pair.html
- watersb 4y ago
  I can't tell exactly from a quick scan of Cringeley's commentary... but I get the impression that a "dry copper pair" the single-pair POTS equivalent of "dark fiber"... with the critical caveat that a dry copper pair can link two points only if they are serviced by the same central telephone company switch.
  - jcrawfordor 4y ago
    A leased loop is any arrangement where a customer pays the telco for a dedicated loop for continuous use. A dry loop is a type of leased loop that isn't connected to any telco equipment, just spliced together to create a continuous circuit (a typical or 'wet' leased loop has at least battery and sometimes dial tone from the telephone switch). It's perfectly possible to get a leased line that spans telco offices, in which case your loop has to be spliced to an interoffice or toll lead (long distance line). In the days before heavy use of multiplexing, toll leads were scarce and so interoffice leased lines were extremely expensive. Dry loops were often sold as burglar alarm circuits because one of the most common uses was for burglar alarm communicators that often operated on polarity reversal - meaning that they applied a potential to the pair and just swapped its polarity when an alarm condition occurred. Of course there were more sophisticated burglar alarm communicators at the time that used telegraphy techniques, but these usually ran on private networks since they could share a bus in a way that was not typical of telco infrastructure (most of these were basically Gamewell systems even if not made by Gamewell proper). In the early days of burglar alarm monitoring, if the monitoring service didn't have a private network (typical in urban areas) they usually installed their monitoring equipment or a multiplexing system at each telephone exchange in the covered area, allowing for more economical dry loops within a single office. Actually this pattern continued well into the '90s with some burglar alarm services using DSL-like high-frequency digital communicators that interacted with a monitoring system that had to be connected to the line card at the telephone exchange.