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.
Relevant article: http://helices.org/commentary/dry_copper_pair.html
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.
1990s AppleTalk networks could work over a single pair. I ran a network with hundreds of Macs for a tech company. Ten buildings in a small campus.
Still remember the day the fire-alarm techs punched down over one of the Macs in the executive office. Not much of a network signal when there's 24 Volts on the same line.
But fibre is so much more versatile if you’re running new cables (unless you want to run power)
Here's a relevant news article about a lawsuit related to this phenomenon:
https://easyreadernews.com/edison-stray-voltage/
https://www.dailybreeze.com/2013/03/19/redondo-beach-woman-a...
https://www.nydailynews.com/news/national/woman-wins-4m-verd...
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.
You can push around 1GHz of bandwidth on the normal hardline-feed line with taps system cable uses, each node is designed to pass by a certain number of households.
Coax is.. cheap, forgiving, easy to terminate, and inexpensive to replace - Fiber is more expensive, unforgiving, and much harder to terminate.
New Zealand has fibre to the home for the majority of a country the side of the eastern seaboard of the US, with only 5 million people, and a lower per-capita GDP.
It's doable. It's just a question of wanting to.
AFAIK fibre is more resilient to catastrophes (like earthquakes[1][2] in Christchurch or California), and having a high speed residential fibre network definitely helped during Covid.
I am uncertain what you mean by “efficient”. Perhaps link to something that backs up your opinion?
[1] https://az659834.vo.msecnd.net/eventsaircancprod/production-...
[2] https://www.researchgate.net/profile/Sonia-Giovinazzi-2/publ...
Speaking about optical modules in this formfactor: https://en.wikipedia.org/wiki/Small_form-factor_pluggable_tr...
I have to see it play out in practice and I'm not a fan of the idea that one telco controls controls (ie stifles competition) in a gpon scenario. The conduit has recently been placed in our street, so "soon"...
Furthermore if you actually run Coax in duct for buried circuits, its easy to replace with fiber later.
I have a 50/8 mbps connection at home and, it gives all the performance it can give. The telco keeps the speeds a bit higher to handle VDSL overhead, so we have a real 50/8 mbps IP connection at premises.
I'd rather not rewire my home and use existing equipment (which can handle 350mpbs), rather than bringing in fragile fiber into the home.
I have Sonic fiber in SF. 1Gbps symmetric, over a "fragile fiber" run directly into my home. It works quite well. The drop cable is pre-made in standard lengths with weatherproof connectors. The glass is embedded in a large-ish diameter substrate that resists sharp bends naturally so the installers don't need to take special care to prevent losses, just don't try to force the cable to bend beyond what it wants to do (very different from your standard fiber patch cables in a switch room). It is robust enough you could cable staple it to a wall without issue. Terminates in a tiny ONT that gives me Ethernet on my side.
They're deploying 10Gbps for all new installs and I'm eagerly awaiting my upgrade. No change to the fiber itself are required, just swapping equipment on both ends. This same fiber can do 100Gbps in the future if the need arises, possibly more. No coax plant can come close. The fact that an independent ISP can do this for $40/month and make money at it proves the economics.
There is no reason not to run fiber unless you're more focused on rent extraction than investing in your business... at least in suburbs and cities. (See ATT's public comments and focus on milking wireless while dis-investing in physical plant as an example of goosing profits because they don't face real competition in most of their service area).
Uhm, no, it's not.
I'm using a 1gbps symmetric connection at the office, for the last decade or so. The network speed is limited by my NIC and the cabling to the switch. The network at the office has more bandwidth (we're the network backbone).
We have fiber ran into our apartment buildings. My apartment's termination box is at the wall across my flat door. On the other hand, the speed I can get from that fiber is not higher than the current VDSL offerings, and they both cap at 100mbps downstream (upstream is probably limited at the same speeds with VDSL). Since the FTTN box is also outside, the speeds and stability from that VDSL connection is rock solid.
For no apparent speed advantage, I need to terminate a thick fiber, and need to run it in the open across the house, drilling walls in the process, or move my house's whole internet infrastructure near it. Both are illogical given the floor plan of my house.
Then comes the equipment part. Again, I'll need to change my core router at home and change everything (I have a mesh network at home), or cascade it to ISPs fiber router, which is another box, more cables, and more management. If the ISP allows me to use my own router, I'd need a media converter from fiber to copper. Which's again more cables, more boxes, more management.
As a result, I'd rather use my house's in-wall cabling to get the speeds I'm happy with instead of getting a shiny (pun intended) technology with no speed advantage.
If the speeds offered here changes over time, I can re-evaluate my choices, but as the xDSL technology gets better, I'm guessing that it'll keep the same speeds with fiber offerings, at least for residential stuff in my area. So, I project that I can upgrade my network speeds at least for a decade without changing my network equipment or cabling.
In the Bay Area they have fiber in SF, South SF, Daly City, Redwood City, Berkley, Oakland, San Carlos, Burlingame, Albany, Brentwood, and probably more. They are rolling it out mostly in areas with poles at the moment because the cost of burying is quite high.
They've proposed "microtrenching" in SF to reach areas with all underground utilities but so far the city hasn't been very interested and it isn't cost-effective for them to dig up the sidewalks to install conduit. I hope that will change at some point.
Of course, for repair work, if a tree or something breaks a multi fiber bundle, splicing is going to be a lot harder than coax. Probably harder than traditional phone lines, but I think PON is setup so that you don't need to care which wire connects to which other wire, and if you do that for end-user traditional phone lines, you'll have a big mess, so you'd really want to match the wires up before you junction them. Coax is just one big wire, so way simpler.
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.
It's not difficult, but it's not miniature. A classic design was a soup-can sized device with a coax connector on each end and a hulking big ground connection on the can. Inside was a spark gap with dime-sized silver contacts, and a few turns of copper busbar as an inductor to smooth out the spike that got past the spark gap. That goes where the cable enters the building. Similar units today tend to be smaller. There will still be serious metal boxes.[1]
You need a serious ground. As in hulking big copper cable to a long ground rod. Grounding to a pipe is no longer allowed; there might be plastic pipe somewhere in the system, either now or in the future.
The next stage is a "central office protector". This is a gas tube with three terminals - both sides of the line, and ground. So it's an enclosed spark gap in an inert gas. An overvoltage will ionize the gas and short it to ground. Telco central offices have one of those on each line. They're plug-in devices that sometimes have to be replaced.
There's a lot of obviously fake stuff on eBay and Amazon in this area. 2D logos superimposed on curved surfaces, even. There's a standard, UL 497B. If it doesn't have that certification, don't buy.
[1] https://www.polyphaser.com/search?Category=Data+Surge+Protec...
I'm a licensed radio amateur since 1996, I've spent about 20 years working in the cellular/telecom/two way radio industry, and I've done Motorola R56 inspections (as well as other proprietary grounding standards).
I respectfully disagree, a direct lightning strike almost certainly will take out gear at a cell site, even when properly grounded. Similarly a direct strike to telco cable will certainly fuse the 16-20ga wire in the cable itself at the first point its near a ground. Carbons, Glass Tubes, and other similar hardware will protect you in the event of a nearby strike (like to a lightning rod on a tower, or building) - but wont save you if the infrastructure is struck itself.
Generally the point of lightning protection systems is to well ground the tower, to draw the lightening away - so the tower and grounding system can protect the equipment - that isn't a direct strike by what I'm saying here - a direct strike would be if it struck the antenna itself.
Thats the perspective I have from cleaning up from strikes at well grounded and protected tower sites.
Data cables aren't usually up that high, fortunately. Power cables, though, are. In some areas high tension towers carry a ground wire between the peaks of the towers for lightning protection. It's impressive to see those systems take repeated direct hits without the lights even flickering. I've seen that in Florida.
Worst case is probably is an AM broadcast station where the tower is isolated from the ground at the base. WSM in Nashville TN is like that. They had a pipe ground vaporized and windows blown out in a lightning strike in December 2019. They lost the tower lighting and some transmission components were damaged, but they apparently stayed on the air.
The Empire State Building takes about 25 lightning hits a year. I wonder what their lightning protection looks like.
There's also the issue of ground bounce. A lightning strike near a house will feed back into the telecommunications and power equipment via the ground rod/plate. I've had experience with plenty of modems getting fried over the years. Some places are just lightning magnets.
Magnetic coupling removes issues with potentials _up to the dielectric breakdown voltage_. Ethernet magnetics are considered high potential components, and even the entry level options will isolate at least 1.5kV, but fault events often exceed that figure.
Magnetic coupling removes issues with _common mode_ potentials. If the + and - side of a pair are both a thousand volts away from the pair on the secondary side, no problem. If a wire pair suddenly measures a thousand volts across… well, Ethernet transformers are typically wound 1:1.
_Ideal_ magnetic coupling removes issues with potentials. Ideal transformers behave as above, but real transformers have parasitic effects, particularly winding capacitance. Fast transients (including ESD) can and do capacitively couple across the transformer from primary to secondary.
Magnetics are important but do not solve the problem on their own. It is possible to design and manufacture electrically robust copper Ethernet systems – for a given definition of robustness (typically defined as passing some specific EMC test) – but even then real world electrical faults can and do destroy robust Ethernet systems. Fiber has none of these concerns.
If it was not floating, you'd get atmospherics, hum, and other issues that you saw in old fashioned ground return systems.
Indeed, measurement of voltage and continuity of T-G and R-G is a standard way to check for faulty cable
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.
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.
My jar of mayo costed $5.50 with tax yesterday.
Sounds like we're playing word games at this point.
Imagine that, a politician playing word games.
Which, as the senior official at DARPA who authorized funding for the project, he kinda did. ;)
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.
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.
You know ... a technology that we could do back in 1986?
It seems like 10baseT1-S is never going to actually come out.
what does sand means in this context please ?
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.