Active Ethernet vs GPON - the price of fibre in South Africa

Johnatan56

Honorary Master
Joined
Aug 23, 2013
Messages
29,728
nobody is saying because you on GPON you will not get the speeds you paying for. Openserv are actually good, their reluctance to sell symmetrical products for a long time and limiting max to 200Mbps down for just as long shows this. They know the risk.

Laurie is taking exception with ISP's/FNO's selling dedicated 1:1 Business services as fact - when in reality the underlying network is unknown at best, he is 100% correct here.

These business then end up paying premium rates for a supposed superior business service when in reality they get the same link as the house next door on the R700 package - they not even split residential/business on the OLT's to apply some sort of QOS. So what they paying extra for? It's a lie in my opinion

Cybersmart guarantees by providing a dedicated wavelength per customer, and they doing that today - you can't really fault that.
You mean e.g. bitco's false advertising? They say 1:1 contention and then in brackets say 1:10 during network congestion, but the line before that says "best-effort SLA". I am guessing they mean from ISP side, since Frogfoot doesn't directly offer business lines, it's through an ISP.

What you pay for is the SLA, how fast they "guarantee" service working again.

RocketNet has a nice page:

And you can see FF guaranteeing 10:1 contention ratio.
Q: I've heard you split the fibre 64 times, and GPON only provides for 2.5Gbps download. Does that not mean a resident would get far less than 1 Gbps if they bought 1 Gbps access?

Not at all. A splitter is essentially a prism, splitting light, and the first time we introduce a splitter is right at the node, where we create a 4:1 split. Closer to the houses, we add another splitter at 16:1, making the overall split on that route 64:1. Should there be a number of close neighbours who all order and make heavy use of 1Gbps services, we will remove the 4:1 splitter for that route, thus dropping the split for the route to 16:1. Because there is 2.5Gbps available, the possible contention is less than 10:1. Practically, it is highly unlikely that so many people will buy 1Gbps services, and if they do, just as unlikely that they will all be using the full 1Gbps at the same time. To use an "old school" analogy, there are not enough telephone trunk lines connecting the suburb's Telkom exchange to the rest of the world to allow every single resident to make an outgoing call at the same time. The economics of telecoms network engineering relies on contention ratios.
So 1:16 means 150Mbps guaranteed per user, so if everyone had a 1Gbps line, you'd get better than 1:10 contention.

So yeah, anyone saying 1:1 is lying, and even on AON you'll just have the contention from the switch back instead, same issue.

Fialkov explained that in their implementation, 40 subscribers could plug into a single switch with an uncontended 1Gbps per client.
This line shows the issue, what is the backhaul of the switch as well? 10Gbps max? So now 250Mbps or 1:4 contention best-case instead.

Cybersmart doing 40Gbps provision for that switch is fine, that will probably be in the apartment block or wherever, since that's where Cybersmart operates, so from that switch to the next switch, does the next switch have 40Gbps backhaul as well to the data center for every switch connected to it? Highly doubt it. What is the end-to-end contention, from end users to e.g. server in Teraco that is off of Cybersmart's network.

“To avoid appearing that we are underdelivering, we limit the service to what is realistically achievable on a speedtest even though it costs the same to provision the service at 1Gbps.”
No it doesn't since handling burst is what is more difficult than handling constant traffic, modern networks you rarely do sustained stuff in a consumer environment, you're loading the next minute of YT or something, one second burst, rest of the time the line is sitting idle.

GPON, on the other hand, is asymmetrical by design. It also lets the fibre operator split a single strand of fibre hundreds of times.
@Jan bad reporting not checking that, max in spec is 128, norm in real-world as max is 1:64, definitely not hundreds
Fialkov explained that GPON generally offers a total of 2.5Gbps of download capacity and 1.25Gbps upload capacity per site.

“This is why you see a lot of asymmetrical services with upload speed half the download, as this mirrors GPON’s total capacity,” said Fialkov.
No, you can have symmetrical on GPON, you just don't do it as home service, you're trying to reduce the number of people who will use it as a home server, or have to plan your network capacity to upload as well, it costs money to do that...
In addition to the asymmetry, GPON also lets network operators split a single fibre strand 128 times — on some implementations up to 512 times.
@Jan again fail to check spec, 512 is 10GPON.
If it’s GPON, it can be contended at the fibre network operator level. On Active Ethernet for services under 1Gbps, there cannot be contention.
No, there's more to it than just client premises to closest switch, still on the last mile provider's side, there's that switch back to another aggregate switch, to probably another aggregate and back.
You have 40 ports you said, you're not going to run all clients / 40 runs back to the data center/directly to internet, that's a lot of fiber.
All AON means is you have a fiber line from custom premises to switch without a splitter in-between, nothing about what happens after the switch (looking from client side).
He also said that with GPON, if the service says 100/100Mbps you have no idea whether the FNO has done that by contending the fibre to minimise their cost per port or kept it uncontended and increased their cost.

“You can be pretty certain that for services less than 1Gbps on an Active Ethernet implementation that the service is uncontended on the FNO level.”
Again, missing the fact that contention doesn't matter that much in a home service, it's if peak burst is handled.

@Jan this is shoddy journalism.

Agreed. Depends on the area - no difference. There are some people saying maintenance in more on aerial, but these days people are just as likely to dig up fibre than they are to drive over the pole.
Define maintenance, aerial is more likely to get damaged in bad weather / tree falling over.

Aerial will require replacement sooner than trenched, just wear and tear, was something like 10-20 for aerial and 20+ easily for trenched, but most of them should be fine for a good 40 years and trenched will probably outlive everyone.
Maintenance isn't the same as DSL/copper, fiber is just check the switches are fine, check light is still coming through (the equipment should report back how much light is coming through, so should be automated for most networks, let's see what actually happens).
 
Last edited:

zAAm

Active Member
Joined
Dec 12, 2016
Messages
63
So yeah, anyone saying 1:1 is lying, and even on AON you'll just have the contention from the switch back instead, same issue.

For residential services, no one will do 1:1 - it will be way too expensive. However, from a layer 1 perspective on GPON, you can dedicate a portion of the 2.5G/1.25G to a specific ONT, which means you can actually do 1:1 if you wanted, but you'll have less bandwidth for the rest of the customers. You would do this for a leased line/dedicated for business over GPON. It won't happen for residential or business internet, and as you say, this will also happen with AE on the backhaul. Contention is a must, but congestion is a design failure.

Define maintenance, aerial is more likely to get damaged in bad weather / tree falling over.

Aerial will require replacement sooner than trenched, just wear and tear, was something like 10-20 for aerial and 20+ easily for trenched, but most of them should be fine for a good 40 years and trenched will probably outlive everyone.
Maintenance isn't the same as DSL/copper, fiber is just check the switches are fine, check light is still coming through (the equipment should report back how much light is coming through, so should be automated for most networks, let's see what actually happens).

Was referring mostly to break fix, and you're right trees do break the fibres. However, with the recent increase in civil works being done by lots of FNOs, for electricity and water etc., the chances of breaking a fibre has increased dramatically. Probably still less than aerial, but then aerial is also much cheaper to install and repair. Also, fibre degrades over time, so you'd be hard pressed to keep the same fibre for 40 years without replacement. And that's not even counting support for new standards with lower loss or dispersion or chromatic abberations etc. Both types have their place though, and one is not necessarily superior from all aspects.
 

KS17

Active Member
Joined
Oct 6, 2020
Messages
67
What about Vuma Reach in the ground?

Also I have seen Vuma aerial fibre and trenched in the same road, just one side is trenched and the other is on the street light poles...
Reach is GPON, which is why the upload is limited to 10
 

cavedog

Honorary Master
Joined
Oct 19, 2007
Messages
19,540
I think the term Vuma Aerial and Vuma Trenched should not be used. They originated from when Vuma acquired Fibrehoods which was a majority Aerial rollout and obviously gpon where the Vuma Trenched was Active Ethernet.

Things have changed a lot since then where Vumatel has also acquired SADV builds which are also gpon.

It would be better to call is Vuma Gpon (Vuma Villages, Vuma Reach, ex Fibrehoods) and Vuma Active Ethernet. For there you can distinguish what you have like Vuma Reach or Vuma Core.

Vumatel is basically just pushing gpon rollouts now and not a crazy with AE anymore as far as I noticed.
 

Johnatan56

Honorary Master
Joined
Aug 23, 2013
Messages
29,728
Was referring mostly to break fix, and you're right trees do break the fibres. However, with the recent increase in civil works being done by lots of FNOs, for electricity and water etc., the chances of breaking a fibre has increased dramatically. Probably still less than aerial, but then aerial is also much cheaper to install and repair. Also, fibre degrades over time, so you'd be hard pressed to keep the same fibre for 40 years without replacement. And that's not even counting support for new standards with lower loss or dispersion or chromatic abberations etc. Both types have their place though, and one is not necessarily superior from all aspects.
Fiber doesn't degrade that fast in trenched, there are already 25+ yo fiber networks, roll-out started in the early 90's, they are all still fine/no degradation AFAIK. Most of the degradation will come from sun shining on it or if strain (like aerial), the actual degradation within the core will be minor and take a pretty long time, think 40 years won't be an issue (sadly only examples I can give are things like NORAD and Chicago's telephone lines from the 1970's, and then GTE in California, but we're talking about late 1970's as that's when the stuff was invented for modern optical fiber, so we're soon to hit 50 years, but so far there's been no reports of issues with age of it anywhere that I can find (and 80% of long-distance transmission has been fiber since the 90's, in the last decade I'd guess it to be near 100%), so doubtful trenched fiber won't outlive us).
Reach is GPON, which is why the upload is limited to 10
No, it's because it's as cheap as possible, look at e.g. 40/10Mbps package, GPON is 2.5/1Gbps, it can handle 20Mbps without an issue if still same contention. It's more to stop people abusing and no one markets the upload, so do as little as can get away with while still being all right experience for majority.
 
Last edited:

Kyoto

Well-Known Member
Joined
Sep 29, 2015
Messages
194
Absolutely, the tech is sound if used as intended.

I'll be nervous as an FNO, GPON is old now, like 2007 ... with the ISP's in ZA only differentiating themselves by either price or speed this is pushing 1Gbps packages to R1k, inevitably this will lead to multiple 1G clients per PON port. While "baseload" can easily be monitored, monitoring for microbursts in this scenario, which can be many 100's of thousands of packets per second and last only milliseconds is not so easy. It's gonna be a problem for some FNO's guaranteed
there are still FNO's using EPON,
 

Geoff.D

Honorary Master
Joined
Aug 4, 2005
Messages
24,601
Contention is a must, but congestion is a design failure.
Rubbish! Contention is the way the telcos have screwed the public for hundreds of years. There is just about no valid reason anymore for any of it.
 

zAAm

Active Member
Joined
Dec 12, 2016
Messages
63
Rubbish! Contention is the way the telcos have screwed the public for hundreds of years. There is just about no valid reason anymore for any of it.
Uhm, unless you're referring to a different definition of the word, every single ISP and FNO and telco in the world contends or oversubscribes their network. Some may choose to do it in the access, or backhaul, or core, or combinations of the former, but every single one does it. Hell, you do it on your home network.

If you do it correctly there will be no impact on your service, if you don't do it correctly, or you don't constantly monitor it, you'll run into problems.
 

Johnatan56

Honorary Master
Joined
Aug 23, 2013
Messages
29,728
Rubbish! Contention is the way the telcos have screwed the public for hundreds of years. There is just about no valid reason anymore for any of it.
You need to understand that contention has become less of an issue now than it was 10 years ago/DSL times.

Most consumers are watching a YT video or Netflix, that's at most 20-30Mbps. Imagine people getting 100Mbps lines, 50Mbps is common enough, they're going to burst their line for 2s or so, then for 8/9 seconds there is little to no usage, in that time someone else can use the bandwidth.

Back when you had 2-4Mbps DSL, someone watching a YT line was 3.2Mbps, you barely managed to have a buffer and were doing something like 80% utilization, and as an ISP Telkom charged you a heck of a lot per Mbps you got, so you wanted to get as little as you could get away with.

Nowadays, most of them terminate at places like Teraco, and usually that's a case of you pay for a port, and then once-off fees for upgrading the port instead of a higher and higher fixed monthly cost, as the data center makes a profit from lots of consumer lines terminating there so businesses will want to host there (closest place to customer, so lowest possible latency which results in better user experience and more likely better sales). So contention became way less of an issue when you have only short bursts. Of course you have some customers doing like 80% of their line constantly, but the higher the line speed, the rarer that is. I do ~400-500GB/month (according to my router's logs) on a 250Mbps line, that's not any different than I did on 50 or 100Mbps, yet the ISP made more money, it's just that I want to be able to burst higher while most of the time my line sits idling, me looking at MyBB having a page load, at a few Mbps and it's already done in a second for another minute.

Of course some are still stuck on DSL, mobile, etc., or you have a crappy provider that allows their network to be congested (when you can't handle the peak burst), but contention ratios don't really mean that much for most residential and probably a majority of business as well (we're talking about <20 person companies which is a majority).
 

Geoff.D

Honorary Master
Joined
Aug 4, 2005
Messages
24,601
Uhm, unless you're referring to a different definition of the word, every single ISP and FNO and telco in the world contends or oversubscribes their network. Some may choose to do it in the access, or backhaul, or core, or combinations of the former, but every single one does it. Hell, you do it on your home network.

If you do it correctly there will be no impact on your service, if you don't do it correctly, or you don't constantly monitor it, you'll run into problems.
The fact that as you claim, they all do does not justify it anymore. And yes, if they do it correctly, most will not notice it but if they screw it up like most do, then everyone notices it.
 
Top