GPON vs AON

quovadis said:
Regarding 2 it's very unlikely that the fibre will experience congestion to the same extent as most of the DSL infrastructure uplinks were and still are copper-based. Copper tech is heavily affected by distance thus there are more points of aggregation/points of congestion to deal with.
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No not true for many years already. From the MSAN into the network has been exclusively on fibre for more than 20 - 25 years or longer even. It may have been on older low capacity fibre systems ( 2, 4, 8 16, 64) x 2 Mbps, but by now there should be no PDH left in the network, some SDHmaybe but unlikely, and the rest all on GE.

The last z-screen copper cable based PCM was eliminated out of the networks years ago (25 -30 years ago).

Can't say the same for mobile networks, which are still quite heavily dependent on Digital Microwave systems.

There may still be too many intermediate traffic aggregation points. But typically a simple trace route will identify what is going one for any specific area.
 
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Geoff.D said:
No not true for many years already. From the MSAN into the network has been exclusively on fibre for for more than 20 - 25 years. It may have been on older low capacity fibre systems ( 2, 4, 8 16, 64) x 2 Mbps, but by now there should be no PDH left in the network, some SDH, and the rest all on GE.

The last z-screen copper cable based PCM was eliminated out of the networks years ago (25 -30 years ago).

Can't say the same for mobile networks, which are still quite heavily dependent on Digital Microwave systems.

There may still be too many intermediate traffic aggreagtion points. But typically a simple trace route will identify what is going one for any specific area.
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Most MSANS were uplinked with fibre however there were plenty of downstream SDC's uplinked to the MSANS with copper. The IMS core and MSANs were only implemented in the early 2010s and before that it was a mixmatch of technologies which are still in use even today by many business customers.
 
Geoff.D said:
No not true for many years already. From the MSAN into the network has been exclusively on fibre for more than 20 - 25 years or longer even. It may have been on older low capacity fibre systems ( 2, 4, 8 16, 64) x 2 Mbps, but by now there should be no PDH left in the network, some SDHmaybe but unlikely, and the rest all on GE.

The last z-screen copper cable based PCM was eliminated out of the networks years ago (25 -30 years ago).

Can't say the same for mobile networks, which are still quite heavily dependent on Digital Microwave systems.

There may still be too many intermediate traffic aggregation points. But typically a simple trace route will identify what is going one for any specific area.
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The point I highlighted in bold is incorrect. When I left Telkom in 2000, z-screen PCM was still in common use. By 2009 yes, they were gone, and existing ones replaced with MARTIS DXX.

Secondly, back in 1999/2000 yes the cartels were heavily using microwave backhaul. This now replaced completely by fibre
 
ArtyLoop said:
The point I highlighted in bold is incorrect. When I left Telkom in 2000, z-screen PCM was still in common use. By 2009 yes, they were gone, and existing ones replaced with MARTIS DXX.

Secondly, back in 1999/2000 yes the cartels were heavily using microwave backhaul. This now replaced completely by fibre
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It does go to show how rapidly the technology has changed. I still have a 384kbps ISA-based x.25 card from the mid-90s which I haven't had the heart to throw away just because of the sheer cost of it.
 
I am surprised that some lingered that long. All should have been out by 1995. That was what the planning called for. But then, that meant the plans had to be implemented.

VC has not got the memo in my area and neither has MTN. Still very actively using Microwave links on the base stations close to me.
 
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quovadis said:
It does go to show how rapidly the technology has changed. I still have a 384kbps ISA-based x.25 card from the mid-90s which I haven't had the heart to throw away just because of the sheer cost of it.
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And my orignal ADSL modem router is still functioning! The replacements after it have all died and broken. It is currently back in service because the 3-year old wi-fi version packed up about a month ago.
 
quovadis said:
I'm not quite sure why you're reverting to thus type of response. It would've been nice if you read my reply. Fibre is not limitless and there will always be an upper limit for obvious reasons - this is a fact - it's not debatable.
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I wasn't talking to you..

I was talking to the "meneer big bandiwtdh user" (anyone?)

stop being so sensitive.

damn.
 
ThatOtherDude said:
contradictory statement of the year.
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I see the irony in the statement is incomprehensible for you and you missed it entirely.

Ironically, I was involved in an exercise carried out by VC which involved a study in how much Microwave bw VC would require to cater for the planned 20-year backhaul capacity requirements. ( in the late 1990's).
The idea was then to ensure that VC would be able to operate entirely independently of Telkom.
Most of us knew what the answer was before we started the exercise, but never the less, we completed the exercise.
We showed the already that ultimately, base stations would have to be interconnected on a fibre based network to ensure the long-term survival of the mobile industry because the available microwave bandwidth would never be available to meet the requirements.
That exercise was then changed to determine "what the total capacity of a two-core optic fibre cable would be
by the year 2010".
So I know a little more than most what is involved in trying to estimate limits. In the end, we used "Moore's Law",
which basically says that the "limits" are not worth worrying about, instead just accept the fact that by the time you need the capacity, it will be available. The important issue was for VC to rather concentrate on getting the regulations changed so that VC could ultimately install its own fibre networks, in parallel with making use of optic fibre capacity from Telkom instead of the continued reliance of microwave links to feed base stations.

The "claimed" limits for optic fibre have been "revised" many times over the years. And it will continue to be the case long after we are all gone.
The current "limits" are actually determined by the technology hanging on to each end of the fibre, not by the medium.

And then, one is faced with how the technology is deployed, which ends up exposing the "limits" imposed on customers.
 
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Geoff.D said:
The "claimed" limits for optic fibre have been "revised" many times over the years. And it will continue to be the case long after we are all gone.
The current "limits" are actually determined by the technology hanging on to each end of the fibre, not by the medium.
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Referring back to my earlier posts, there’s a limit for every communication medium and the Shannon Limit is fascinating reading especially considering it’s 70 years old.
 
quovadis said:
Referring back to my earlier posts, there’s a limit for every communication medium and the Shannon Limit is fascinating reading especially considering it’s 70 years old.
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Yes absolutely. Every single new technology that comes along is always evaluated against Shannon's Law. He was able to step out of whatever technology there was at the time and distill out the absolute basics and come up with a fundamental relationship that would always be true based on physics.
It was the very first principal we were taught, long before we ever even got the basics of communications. It does not matter what technology you are dealing with, from a 2-wire farm line to Tbps Fibre system, that basic relationship is so far always the limiting factor.
 
The full name for Shannon's Law is the Shannon-Hartley Law, because what Shannon did was build on the earlier work of Hartley. Hartley's work built on even earlier work by Nyquist and others.
One forgets that modern digital technologies were NOT the first time a digital system was ever used.

Smoke signals could arguably be considered the first followed by heliographs and the Telex. Then everything moved into analogue voice before getting back to Digital.

A short history:

During the late 1920s, Harry Nyquist and Ralph Hartley developed a handful of fundamental ideas related to the transmission of information, particularly in the context of the telegraph as a communications system. At the time, these concepts were powerful breakthroughs individually, but they were not part of a comprehensive theory. In the 1940s, Claude Shannon developed the concept of channel capacity, based in part on the ideas of Nyquist and Hartley, and then formulated a complete theory of information and its transmission.
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1927: Nyquist Pulse Rate f ≤ 2B (B = Channel Analogue Bandwidth (Hz)
1928: Hartley defined the term "Line Rate" = "data signalling rate" R b/s (or Digital Bandwidth R)
R = f log^2 (M) or the more useable form of R ≤ 2B Log^2 (M) where M = the maximum number of distinct pulses.
1948: Shannon's Law: C = B log^2[1+S/N]where C = channel capacity; S = Signal; N = Noise

And the combined relationship of 2B Log^2(M) = B log^2[1+S/N] ===> M = √(1 + S/N)

Absolutely everything in information theory and communications depends on the above very simple concepts.
It does not matter whether it is an old analogue copper channel, a satellite channel or a modern "fibre channel" on an optic fibre cable.

Go and look at any analysis of a link budget for a channel in all fields, and while some different terms are used for the parameters (heaven alone knows why), the formulas are always the same.
 
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When I heard of VUMA's Active vs other GPON networks, I knew 100% that I needed to get VUMA in my area, and succeed in getting my HOA to let VUMA trenched in and not another circus. Being a 1gbps customer, I am very happy.
Have friends with Metro nearby, and have been able to diagnose their network is shot with congestion, be it the GPON setup or the local POP being too contended now.

Heck, even Afrihost have a notice about it that has been up for days, showing there must be a problem somewhere:
https://www.afrihost.com/site/network_status#fibre

The only issue I had with VUMA was seeing other peoples traffic once, and getting traffic addressed to them on my ONT. Got hold of my SP about it, and they got VUMA in the loop. It wasn't a big deal with me having a large line, but a 4MB subscriber would have been killed by it. Turned out it was a switch that had some or other problem, and it was resolved.

Downside though, I guess GPON can be cheaper, I have noticed prices on VUMA can be higher than others.
 
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