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Doing gigabit Ethernet over my British phone wires

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Re: Doing gigabit Ethernet over my British phone wires

#211

Post by user5994461 »

simoncion wrote: post #76
bjackman wrote: post #37

Wait, but you get 63MB/s down from steam? My internet is pretty good, I can easily saturate my (rather dated) WiFi at about 30MB/s. But Steam downloads are extremely slow for me (can't remember the numbers but much less). I always assumed Valve themselves were just stingy with bandwidth. Something else funny going on?

> Wait, but you get 63MB/s down from steam? I usually (but not always) saturate my downlink with Steam downloads... even back when I was a Comcast customer and paying for ~180MB/s (~1500mbit/s) asymmetric service. I believe that I have noticed that smaller games (~a few hundred MB or maybe a GB or two) will download quite a bit slower than large games, but I'm not very confident in that observation.

> I believe that I have noticed that smaller games (~a few hundred MB or maybe a GB or two) will download quite a bit slower than large games, but I'm not very confident in that observation.

You can see that on the HellDivers screenshot, it takes 20 seconds to reach 500 Mbps, because TCP takes a while to adjust the bandwidth and is very conservative. TCP and home computers are not designed to make use of gigabit connections.

Re: Doing gigabit Ethernet over my British phone wires

#212

Post by tialaramex »

user5994461 wrote: post #206
tialaramex wrote: post #89

Earlier quoted context omitted.

That's also a good point that the Network hardware does not care about cable categories. If it plugs into your card the card goes "OK, lets see if 1000baseT fits on this?" the cables don't have a little chip or anything saying "I'm not suitable for high speed" the card will figure out whether this looks plausible and just do it. At the turn of the century I was putting new Cisco gear into a building (which has since…

> the cables don't have a little chip or anything saying "I'm not suitable for high speed" the card will figure out whether this looks plausible and just do it. You're actually wrong on all of that ^^ The cables actually have a rating to say what they are suitable to. See the markings on the cable: category Cat5/Cat5e/Cat6 + frequency range 100/250 Mhz + insulation UTP/FTP/STP/mix. Ethernet cards don't negotiate, the…

It's true that the cable says 5e on it but your device doesn't read the printed reading so it doesn't matter.

That printed category tells you what was tested, not whether the cable works in practice. Which makes sense, but leads to the consequence I described.

Re: Doing gigabit Ethernet over my British phone wires

#213

Post by robocat »

direwolf20 wrote: post #124
estimator7292 wrote: post #98

Earlier quoted context omitted.

1000Base-T uses two pairs per direction, actually. It's full duplex. Each port sees two TX and two RX pair. There are four pair of wires in the cable. If you use all of them for TX, you can't receive.

That's not true. https://en.wikipedia.org/wiki/Gigabit_Ethernet#1000BASE%E2%8...

Relevant section:

  Autonegotiation is a requirement for 1000BASE-T implementations as minimally the clock source for the link has to be negotiated, as one endpoint must be master and the other endpoint must be slave.

  1000BASE-T uses four cable pairs for simultaneous transmission in both directions through the use of echo cancellation with adaptive equalization. Line coding is five-level pulse-amplitude modulation (PAM-5).

  Since autonegotiation takes place on only two pairs, if two 1000BASE-T interfaces are connected through a cable with only two pairs, the interfaces will complete negotiation and choose gigabit as the best common operating mode, but the link will never come up because all four pairs are required for data communications.

  Each 1000BASE-T network segment is recommended to be a maximum length of 100 meters and must use Category 5 cable or better.

  Automatic MDI/MDI-X configuration is specified as an optional feature in the standard that is commonly implemented. This feature makes it safe to incorrectly mix straight-through and crossover-cables, plus mix MDI and MDI-X devices.
(Slight edits)

Re: Doing gigabit Ethernet over my British phone wires

#214

Post by anonymousiam »

estimator7292 wrote: post #98
direwolf20 wrote: post #69

Earlier quoted context omitted.

Gigabit Ethernet uses four pairs per direction. It uses the same four pairs in both directions at the same time.

1000Base-T uses two pairs per direction, actually. It's full duplex. Each port sees two TX and two RX pair. There are four pair of wires in the cable. If you use all of them for TX, you can't receive.

1000Base-T uses four pairs in both directions at the same time. It does this through the use of a hybrid in the PHY that subtracts what is being transmitted from what is received on the wires. 802.3ab is a fairly complicated specification with many layers of abstraction. I spent a few months studying it for a project about a decade ago.

Re: Doing gigabit Ethernet over my British phone wires

#215

Post by cyberax »

irl_zebra wrote: post #191
raddan wrote: post #175

Earlier quoted context omitted.

Ahh! Don’t replace your coax with Cat5e/6! Coaxial cable has excellent noise rejection—better than Cat5e. Instead, get a MoCA adapter like this one [1]. You can get 2.5Gbps over coax! [1] https://a.co/d/e2FYGWj

I was resigned to running cat6e up three floors because there was only coax and I needed a wifi AP up there. Came across the moca solution and it's great. I get flawless 2.5gbe from the basement switch to the third floor over coax. It's basically a little device that connects at each end of the coax and cat6 goes in and out. Cat 6 would be better though so I could run POE from the basement switch to power the wifi AP…

You can run power over coax! You can buy power-injecting splitters that were used to power old analog cameras. They basically just connect the cable to the 12V, sometimes directly but usually through some current-limiting safety switch.

MoCA devices have a 100 Ohm internal resistor at the end to limit the cable echoes, so they are not affected by the DC on the cable.

Re: Doing gigabit Ethernet over my British phone wires

#216

Post by tomatocracy »

Reason077 wrote: post #105
jakub_g wrote: post #4

> Basically, you need to follow the tracking regularly until the package is tagged as lost or failed delivery, which is the cue to pay import fees. > It’s the normal procedure to buy things from Europe since Brexit 2020. It’s actually quite shocking that Royal Mail still hasn’t updated their tracking system to be able to give a status “waiting on import fees to be paid online”. They had 6 years! Wow.

> "Paid the fee online, 20% VAT + a few pounds of handling fees ... It’s the normal procedure to buy things from Europe since Brexit 2020." Why don't Amazon and other online retailers just charge you the UK VAT when you order and ship it "VAT paid", so it doesn't get held up at the border? That's how it works in New Zealand. You pay New Zealand's GST when you place an order, not after it arrives. Any online retailer…

This is exactly how it works in the UK for purchases worth £135 or less which are shipped directly from outside the UK. The retailer has to charge UK VAT as if it were a domestic sale at the point of sale, and there is then nothing to pay at customs so no hold-up for that. It's only consignments worth over £135 where it ends up being stopped for payment at import.

On top of that, Amazon and other large online retailers also have a huge distribution and warehouse network domestically in the UK already so for higher value items mostly they import themselves to their warehouses before sale and then sales are purely domestic.

Re: Doing gigabit Ethernet over my British phone wires

#217

Post by user5994461 »

iamcalledrob wrote: post #39
Quarrel wrote: post #11

Earlier quoted context omitted.

He claims: > One peculiar thing from the UK: Internet providers don’t truly offer gigabit internet. Which might well be true where he is (ie he's limited to the equivalent of shared HFC or xDSL), but certainly isn't true everywhere. I've had gigabit fibre (full duplex) in London since 2016, and the building had it before I arrived. It also has incredibly low latency to the major data centres of London, and not a lot…

Symnetric gigabit connections can be hard to come by in London. If you're served by a niche fibre provider (e.g. Hyperoptic, Community Fibre) then you're golden. There's Virgin (think Comcast) with paltry upload speeds due to the cable tech. Understandable though not ideal. Then there's the OpenReach full fibre network with paltry upload speeds due to... ??? there appears to no good reason, other than not wanting to…

> Does anyone actually know why they don't offer a symmetric product like the niche fibre ISPs?

Short version: The UK regulator OFCOM defines ultrafast internet as 30 Mbps download speed. That's why UK internet providers (openreach and related) have deals starting as low as 30 Mbps and they can't be arsed to provide a faster speed (unless you pay £££).

Re: Doing gigabit Ethernet over my British phone wires

#218

Post by y1n0 »

stefan_ wrote: post #182
manbart wrote: post #152

Earlier quoted context omitted.

Gigabit Ethernet require 4 twisted pairs i.e. 8 individual cables. 100Mb Ethernet requires 2 pairs i.e. 4 individual cables. At least in standard configuration

There is a standard for Gbit over a single pair: Single Pair Ethernet (SPE). But it's more of a rare automotive thing, so I'm also confused how the grandparent made this work.

Used on rockets too. Harnessing is a major contributor to non-payload mass.

Re: Doing gigabit Ethernet over my British phone wires

#219

Post by userbinator »

mortenlarsen wrote: post #12
userbinator wrote: post #7

It sounds like his phone lines were already cat5, which is not surprisingly capable of 1Gbps. However, I wonder why it seems G.hn is only available in the form of adapters, and not as e.g. a PCIe NIC.

Then they would need to deal with drivers.

You could have a regular single-chip Ethernet NIC on the same card.

Re: Doing gigabit Ethernet over my British phone wires

#220

Post by mrandish »

anonymousiam wrote: post #210
mrandish wrote: post #209

Some of the OP's RJ11 runs apparently only have two wires connected, which may be a UK thing (or just a 'bad contractor thing'). Hence resorting to a solution that that can put broadband on two or four unshielded phone wires (probably based on ADSL-type signaling). In the US, houses built to code in the last 30-40 years generally have 4-wire runs to RJ-11 jacks. TFA doesn't mention it but it is possible (although hac…

My latest house, built about eight years ago, came with CAT6A cabling for all of the phones. That made it really easy to just replace all of the RJ11 jacks with RJ45 (or 8P8C if you like to call them that). They've been providing POE+ gigabit Ethernet for the past seven years, and I'm about to upgrade them to 10GBase-T.

I envy you. Must be nice to open up a wall jack and be pleasantly surprised instead of bitterly disappointed :-).

I recently built a vacation property and could choose what to install. Initially, I was thinking CAT6A but after getting some good quality plenum-rated 6A to play with, I discovered it's surprisingly thick and doesn't bend very easily (minimum corner radii to avoid shield damage are actually specced) and it's not exactly easy to DIY new connectors on them correctly if you don't do it all the time.

So, after really considering the max throughput I'm ever likely to actually use, I decided to go with some good CAT6. It wasn't even a cost thing, as the difference was negligible. It was just practical reality. None of the runs are very long and I should be able to get up to 10gbps on 6A, although I doubt I'll ever use more than 2.5gbps (only using 1gbps today). One factor is the property is off-grid except for AC, so data is via StarLink anyway and fiber won't ever happen out there. While LEO satellite and terrestrial cellular speeds will increase in coming years, when more than 2.5gpbs is available - it'll almost certainly be priced to maximize B2B profit and we probably wouldn't pay that for a vacation house (because this is the US, not someplace that prices broadband rationally like Korea).

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