Re: [AFMUG] PON question

[Josh Luthman]

If you have an *ACTIVE* cabinet in the neighborhood, that means you
have electronics & batteries & an uplink fiber to feed it.  You'll also
need another fiber in another direction.  If I were to do things in town,
that would make sense.

In my case I'm in the middle of nowhere so I have all of my customers all
going to one solid concrete building (gas generator, LP generator, weeks
worth of batteries) and a 100% underground plant.  My only concern is
illegal digging in the ROW.

On Sat, Mar 16, 2024 at 5:45 PM Ken Hohhof  wrote:

> Mike Hammett kind of touched on what I was asking and why.  I was told
> that Metronet near me had a hut in Batavia that also served St. Charles,
> Geneva, West Chicago, etc.  via PON.
>
>
>
> Also a company that built a middle mile / anchor institution fiber network
> with a BTOP grant 12+ years ago convinced the county to let them take it
> private, and they have run aerial fiber in most of Shabbona which is one of
> the towns Mike mentioned.  With my misconception about how FTTH is
> typically deployed, I expected there to be at least one cabinet or hut in
> town.  But I think they are just using strands from the BTOP project and
> feeding it passively from a distant town.
>
>
>
> I would prefer to see more redundancy, especially since both buried and
> aerial fiber definitely gets damaged around here, but I guess practical
> results matter more than what-ifs.  At least local power outages shouldn’t
> take it down, and a central NOC or hut should be able to have serious
> battery and/or generator backup.
>
>
>
>
>
> *From:* AF  *On Behalf Of *Josh Luthman
> *Sent:* Saturday, March 16, 2024 4:12 PM
> *To:* AnimalFarm Microwave Users Group 
> *Subject:* Re: [AFMUG] PON question
>
>
>
> PON is one port at your end and then goes through splitters that reduce
> light and add ports to end up at customer ONTs.  1:128 is pretty short
> range and high customer count - we could never do that in a rural plant
> (5-15 miles).  Maybe 1:64 but that's about the limit.  There is NO
> redundancy in PON.  Best you could do is 2x32 or whatever splitters which
> is where you feed the downstream fiber with two PON ports.  An engineer
> from Metronet told me they did that but no one could ever answer why
> (technically or operationally).   Think like you have an AP on a tower
> feeding 32 customers.  What are the chances you have an AP right below it
> with the same SSID/PSK/frequency for the customers to connect to if the
> first AP goes down?
>
>
>
> Think of Active E like a bunch of dumb switches.  You have a 48 port
> switch that goes to 48 customers using 48 fibers.  If the fiber feeding the
> switch goes down, it can go to a different fiber/uplink port.
>
>
>
> On Fri, Mar 15, 2024 at 7:59 PM Ken Hohhof  wrote:
>
> Since there are FTTH people here and I’m mostly ignorant of such things,
> maybe someone can clear something up for me.
>
>
>
> I always assumed a PON based FTTH system had a topology kind of like HFC.
> I expected fiber down the street with splitters, but fed by some sort of
> neighborhood node in a cabinet with power and electronics, fed by active
> EPL style fiber.  Which could have redundant paths, rings, etc. so a fiber
> cut wouldn’t take down a whole town or multiple towns, the backbone traffic
> would reroute.
>
>
>
> I’ve been told this is not the case.  And that instead, each PON could go
> back over a strand to a headend several towns and many miles away, all
> passive.
>
>
>
> Sorry for the poor description of my question, hopefully you can figure
> out what I’m asking.
>
> --
> AF mailing list
> AF@af.afmug.com
> http://af.afmug.com/mailman/listinfo/af_af.afmug.com
>
> --
> AF mailing list
> AF@af.afmug.com
> http://af.afmug.com/mailman/listinfo/af_af.afmug.com
>
-- 
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Re: [AFMUG] PON question

[dmmoffett]

Since I like to give too much detail:

 

Range

The TDM timing gives you a “maximum differential reach”.  I’ve read that it’s 
20km on GPON, 40km on XGS-PON, and 100km on NG-PON2.  I haven’t read the actual 
ITU specs, but those numbers were touted to be the “standard”.  Whether that’s 
true or not: In the real world, our Nokia platform lets us configure both GPON 
and XGS to 40km differential.  The “differential reach” is the difference 
between the nearest and furthest ONT.  So if our nearest ONT is 20km down the 
line, then the furthest could be 60km.  Someone said XGS could go 100km.  That 
might mean their vendor lets them configure a higher differential reach, or 
that might be assuming the first splitter is 60km away.  It’s a true statement 
either way, but at 100km it’ll be at the razor’s edge of the link budget.

 

The loss from distance is something like 0.2-0.5db/Km, it depends on the 
wavelength. It’s worse if the fiber is very old because manufacturing methods 
have improved the attenuation.  If it’s old plant you’d have to get the part 
numbers off the cable and look up specs.  I’m not sure how old it has to be to 
matter.  I have not seen fiber old enough where that mattered, so that’s an 
academic topic for me.  

 

Fusion splices can be as low as 0.02dB attenuation, but I think the typical 
standard is 0.2dB or better is acceptable.  Connectors vary, but you can say 
0.5dB and it shouldn’t be worse than that.

 

Most of your losses come from splitters, and that’ll be exactly what you’d 
expect.  3dB every time you cut it in half, plus maybe 0.5-1 for insertion 
loss. 

 

On C+ optics you start with a tx power of +6-+7dBm.  Receiver sensitivity at 
the ONT could vary, but -28dBm is typical.  The uplink wavelength has more 
attenuation, but the ONT has a little more Tx power and the OLT has a little 
more sensitivity.  So if it’s good in one direction it’s probably good in the 
other one.  We target -20 so we have plenty of margin.  So we have some room to 
cut it a little closer when we have to, like adding a splitter for a duplex 
that was originally counted as a 1 family home during our planning, or losses 
from repairs, or whatever.  The spec sheet for our everyday ONT says 
sensitivity is -28.5 at BER e10-3, which is an acceptable BER with FEC enabled. 
 So in perfect conditions with a straight shot from the OLT to the ONT and no 
splices I could get 118km.  I don’t think they sell 118km reels, so that’s not 
realistic, but 100km figure isn’t crazy.  Realistically you won’t do that 
because you’ll have splitters.  If you were going to dedicate a whole fiber at 
that distance to one customer then you’d probably do Ethernet with long range 
transceivers.  With that much plant dedicated to them they’re hopefully paying 
a mint.

 

So yeah.  You could design with small nodes close to the customer, or you could 
design with one awesome POP reaching several towns.  Either way is doable.

 

 

Redundancy

It’s possible.  Google search for PON Type B and Type C protection.  

There are some fun little diagrams from Huawei here:

https://forum.huawei.com/enterprise/en/hcip-access-01-gpon-type-b-protection-technology/thread/667281720950538240-667213871523442688

https://forum.huawei.com/enterprise/en/hcip-access-02-gpon-type-c-protection-technology/thread/667281974273916929-667213871523442688

 

I have never done it, and I don’t know who does do it.  I’m not even sure if 
our Nokia equipment supports it.  You’ll spend twice the money on OLT capacity, 
and you’d lose ~3.5dB from the link budget to split the path to two OLT’s.  
You’d consequently spend twice as much on power and all that goes with that 
(battery backup, generator capacity, air conditioning, space).  The extra 1x2 
split could potentially cut the number of subs on the circuit by as much as 
half.  I haven’t done the math to confirm whether it’s worth it or not, but on 
the surface it sounds like it wouldn’t be. 

 

We’ve had bad transceivers and bad line cards, but not very often.  In the 
market I’m responsible for I’ve had 3 transceivers fail in 3 years, and there 
are over a thousand deployed here.  I can live with 0.3% failures on that time 
scale.  I had one bad line card, but it had a dead port out of the box.  I 
haven’t had one fail in service yet.  Power failures happen, but when we’re 
building a POP to serve 12,000 households we’re not going to skimp on 
batteries.  So redundancy would be nice to have, and someone must do it, but 
I’d have a hard time making the business case to my superiors.  If we were 
charging top dollar for an enterprise/SMB service that might be a way to 
differentiate and justify the higher price.

 

 

 

 

From: AF  On Behalf Of Ken Hohhof
Sent: Saturday, March 16, 2024 5:40 PM
To: 'AnimalFarm Microwave Users Group' 
Subject: Re: [AFMUG] PON question

 

Mike Hammett kind of touched on what I was asking and why.  I was told that 
Metronet near me had a hut in Batavia that a

Re: [AFMUG] PON question

[Mike Hammett]

hah, I know. I had to go in and turn some servers back on. The facility average 
maxed at 120. One of the NTT divisions lost two core routers because their cage 
crossed 130. 

I'm looking at a ring of 88 to 350 to 717 S. Wells to 427 S. LaSalle to 90. 
Well, if I can get the buy-in from upstairs. I can pick up most of my peers in 
427 and I can then meet my 911 peer in 717. 




- 
Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 




- Original Message -

From: "Ken Hohhof"  
To: "AnimalFarm Microwave Users Group"  
Sent: Saturday, March 16, 2024 7:05:22 PM 
Subject: Re: [AFMUG] PON question 



Equinix has a really big hut in Chicago that was overheating. 



From: AF  On Behalf Of Mike Hammett 
Sent: Saturday, March 16, 2024 6:51 PM 
To: AnimalFarm Microwave Users Group  
Subject: Re: [AFMUG] PON question 


"a hut in Batavia" 



and that hut was overheating last summer, resulting in a bunch of rolling 
outages. 



- 
Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 




- Original Message -


From: "Ken Hohhof" < khoh...@kwom.com > 
To: "AnimalFarm Microwave Users Group" < af@af.afmug.com > 
Sent: Saturday, March 16, 2024 4:39:44 PM 
Subject: Re: [AFMUG] PON question 
Mike Hammett kind of touched on what I was asking and why. I was told that 
Metronet near me had a hut in Batavia that also served St. Charles, Geneva, 
West Chicago, etc. via PON. 

Also a company that built a middle mile / anchor institution fiber network with 
a BTOP grant 12+ years ago convinced the county to let them take it private, 
and they have run aerial fiber in most of Shabbona which is one of the towns 
Mike mentioned. With my misconception about how FTTH is typically deployed, I 
expected there to be at least one cabinet or hut in town. But I think they are 
just using strands from the BTOP project and feeding it passively from a 
distant town. 

I would prefer to see more redundancy, especially since both buried and aerial 
fiber definitely gets damaged around here, but I guess practical results matter 
more than what-ifs. At least local power outages shouldn’t take it down, and a 
central NOC or hut should be able to have serious battery and/or generator 
backup. 



From: AF < af-boun...@af.afmug.com > On Behalf Of Josh Luthman 
Sent: Saturday, March 16, 2024 4:12 PM 
To: AnimalFarm Microwave Users Group < af@af.afmug.com > 
Subject: Re: [AFMUG] PON question 


PON is one port at your end and then goes through splitters that reduce light 
and add ports to end up at customer ONTs. 1:128 is pretty short range and high 
customer count - we could never do that in a rural plant (5-15 miles). Maybe 
1:64 but that's about the limit. There is NO redundancy in PON. Best you could 
do is 2x32 or whatever splitters which is where you feed the downstream fiber 
with two PON ports. An engineer from Metronet told me they did that but no one 
could ever answer why (technically or operationally). Think like you have an AP 
on a tower feeding 32 customers. What are the chances you have an AP right 
below it with the same SSID/PSK/frequency for the customers to connect to if 
the first AP goes down? 



Think of Active E like a bunch of dumb switches. You have a 48 port switch that 
goes to 48 customers using 48 fibers. If the fiber feeding the switch goes 
down, it can go to a different fiber/uplink port. 



On Fri, Mar 15, 2024 at 7:59 PM Ken Hohhof < khoh...@kwom.com > wrote: 





Since there are FTTH people here and I’m mostly ignorant of such things, maybe 
someone can clear something up for me. 

I always assumed a PON based FTTH system had a topology kind of like HFC. I 
expected fiber down the street with splitters, but fed by some sort of 
neighborhood node in a cabinet with power and electronics, fed by active EPL 
style fiber. Which could have redundant paths, rings, etc. so a fiber cut 
wouldn’t take down a whole town or multiple towns, the backbone traffic would 
reroute. 

I’ve been told this is not the case. And that instead, each PON could go back 
over a strand to a headend several towns and many miles away, all passive. 

Sorry for the poor description of my question, hopefully you can figure out 
what I’m asking. 
-- 
AF mailing list 
AF@af.afmug.com 
http://af.afmug.com/mailman/listinfo/af_af.afmug.com 



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Re: [AFMUG] PON question

[Ken Hohhof]

Equinix has a really big hut in Chicago that was overheating.

 

From: AF  On Behalf Of Mike Hammett
Sent: Saturday, March 16, 2024 6:51 PM
To: AnimalFarm Microwave Users Group 
Subject: Re: [AFMUG] PON question

 

"a hut in Batavia"

 

and that hut was overheating last summer, resulting in a bunch of rolling 
outages.



-
Mike Hammett
 <http://www.ics-il.com/> Intelligent Computing Solutions
 <https://www.facebook.com/ICSIL>  
<https://plus.google.com/+IntelligentComputingSolutionsDeKalb>  
<https://www.linkedin.com/company/intelligent-computing-solutions>  
<https://twitter.com/ICSIL> 
 <http://www.midwest-ix.com/> Midwest Internet Exchange
 <https://www.facebook.com/mdwestix>  
<https://www.linkedin.com/company/midwest-internet-exchange>  
<https://twitter.com/mdwestix> 
 <http://www.thebrotherswisp.com/> The Brothers WISP
 <https://www.facebook.com/thebrotherswisp>  
<https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> 




  _  

From: "Ken Hohhof" mailto:khoh...@kwom.com> >
To: "AnimalFarm Microwave Users Group" mailto:af@af.afmug.com> >
Sent: Saturday, March 16, 2024 4:39:44 PM
Subject: Re: [AFMUG] PON question

Mike Hammett kind of touched on what I was asking and why.  I was told that 
Metronet near me had a hut in Batavia that also served St. Charles, Geneva, 
West Chicago, etc.  via PON.

 

Also a company that built a middle mile / anchor institution fiber network with 
a BTOP grant 12+ years ago convinced the county to let them take it private, 
and they have run aerial fiber in most of Shabbona which is one of the towns 
Mike mentioned.  With my misconception about how FTTH is typically deployed, I 
expected there to be at least one cabinet or hut in town.  But I think they are 
just using strands from the BTOP project and feeding it passively from a 
distant town.

 

I would prefer to see more redundancy, especially since both buried and aerial 
fiber definitely gets damaged around here, but I guess practical results matter 
more than what-ifs.  At least local power outages shouldn’t take it down, and a 
central NOC or hut should be able to have serious battery and/or generator 
backup.

 

 

From: AF mailto:af-boun...@af.afmug.com> > On Behalf 
Of Josh Luthman
Sent: Saturday, March 16, 2024 4:12 PM
To: AnimalFarm Microwave Users Group mailto:af@af.afmug.com> >
Subject: Re: [AFMUG] PON question

 

PON is one port at your end and then goes through splitters that reduce light 
and add ports to end up at customer ONTs.  1:128 is pretty short range and high 
customer count - we could never do that in a rural plant (5-15 miles).  Maybe 
1:64 but that's about the limit.  There is NO redundancy in PON.  Best you 
could do is 2x32 or whatever splitters which is where you feed the downstream 
fiber with two PON ports.  An engineer from Metronet told me they did that but 
no one could ever answer why (technically or operationally).   Think like you 
have an AP on a tower feeding 32 customers.  What are the chances you have an 
AP right below it with the same SSID/PSK/frequency for the customers to connect 
to if the first AP goes down?

 

Think of Active E like a bunch of dumb switches.  You have a 48 port switch 
that goes to 48 customers using 48 fibers.  If the fiber feeding the switch 
goes down, it can go to a different fiber/uplink port.

 

On Fri, Mar 15, 2024 at 7:59 PM Ken Hohhof mailto:khoh...@kwom.com> > wrote:

Since there are FTTH people here and I’m mostly ignorant of such things, maybe 
someone can clear something up for me.

 

I always assumed a PON based FTTH system had a topology kind of like HFC.  I 
expected fiber down the street with splitters, but fed by some sort of 
neighborhood node in a cabinet with power and electronics, fed by active EPL 
style fiber.  Which could have redundant paths, rings, etc. so a fiber cut 
wouldn’t take down a whole town or multiple towns, the backbone traffic would 
reroute.

 

I’ve been told this is not the case.  And that instead, each PON could go back 
over a strand to a headend several towns and many miles away, all passive.

 

Sorry for the poor description of my question, hopefully you can figure out 
what I’m asking.

-- 
AF mailing list
AF@af.afmug.com <mailto:AF@af.afmug.com> 
http://af.afmug.com/mailman/listinfo/af_af.afmug.com


-- 
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Re: [AFMUG] PON question

[Mike Hammett]

Probably South Elgin too. Maybe North Aurora. 

They have a hut at the same Oswego water tower that I'm at too. 


I have glass in front of their Sycamore hut. They were the cheapest 100G wave 
into 350 E. Cermak, but I'm taking a hard look at getting my own dark in so I 
can light it with whatever I want. 




- 
Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 




- Original Message -

From: "Ken Hohhof"  
To: "AnimalFarm Microwave Users Group"  
Sent: Saturday, March 16, 2024 4:39:44 PM 
Subject: Re: [AFMUG] PON question 



Mike Hammett kind of touched on what I was asking and why. I was told that 
Metronet near me had a hut in Batavia that also served St. Charles, Geneva, 
West Chicago, etc. via PON. 

Also a company that built a middle mile / anchor institution fiber network with 
a BTOP grant 12+ years ago convinced the county to let them take it private, 
and they have run aerial fiber in most of Shabbona which is one of the towns 
Mike mentioned. With my misconception about how FTTH is typically deployed, I 
expected there to be at least one cabinet or hut in town. But I think they are 
just using strands from the BTOP project and feeding it passively from a 
distant town. 

I would prefer to see more redundancy, especially since both buried and aerial 
fiber definitely gets damaged around here, but I guess practical results matter 
more than what-ifs. At least local power outages shouldn’t take it down, and a 
central NOC or hut should be able to have serious battery and/or generator 
backup. 



From: AF  On Behalf Of Josh Luthman 
Sent: Saturday, March 16, 2024 4:12 PM 
To: AnimalFarm Microwave Users Group  
Subject: Re: [AFMUG] PON question 


PON is one port at your end and then goes through splitters that reduce light 
and add ports to end up at customer ONTs. 1:128 is pretty short range and high 
customer count - we could never do that in a rural plant (5-15 miles). Maybe 
1:64 but that's about the limit. There is NO redundancy in PON. Best you could 
do is 2x32 or whatever splitters which is where you feed the downstream fiber 
with two PON ports. An engineer from Metronet told me they did that but no one 
could ever answer why (technically or operationally). Think like you have an AP 
on a tower feeding 32 customers. What are the chances you have an AP right 
below it with the same SSID/PSK/frequency for the customers to connect to if 
the first AP goes down? 



Think of Active E like a bunch of dumb switches. You have a 48 port switch that 
goes to 48 customers using 48 fibers. If the fiber feeding the switch goes 
down, it can go to a different fiber/uplink port. 



On Fri, Mar 15, 2024 at 7:59 PM Ken Hohhof < khoh...@kwom.com > wrote: 





Since there are FTTH people here and I’m mostly ignorant of such things, maybe 
someone can clear something up for me. 

I always assumed a PON based FTTH system had a topology kind of like HFC. I 
expected fiber down the street with splitters, but fed by some sort of 
neighborhood node in a cabinet with power and electronics, fed by active EPL 
style fiber. Which could have redundant paths, rings, etc. so a fiber cut 
wouldn’t take down a whole town or multiple towns, the backbone traffic would 
reroute. 

I’ve been told this is not the case. And that instead, each PON could go back 
over a strand to a headend several towns and many miles away, all passive. 

Sorry for the poor description of my question, hopefully you can figure out 
what I’m asking. 
-- 
AF mailing list 
AF@af.afmug.com 
http://af.afmug.com/mailman/listinfo/af_af.afmug.com 


-- 
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AF@af.afmug.com 
http://af.afmug.com/mailman/listinfo/af_af.afmug.com 

-- 
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AF@af.afmug.com
http://af.afmug.com/mailman/listinfo/af_af.afmug.com

Re: [AFMUG] PON question

[Mike Hammett]

"a hut in Batavia" 


and that hut was overheating last summer, resulting in a bunch of rolling 
outages. 




- 
Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 




- Original Message -

From: "Ken Hohhof"  
To: "AnimalFarm Microwave Users Group"  
Sent: Saturday, March 16, 2024 4:39:44 PM 
Subject: Re: [AFMUG] PON question 



Mike Hammett kind of touched on what I was asking and why. I was told that 
Metronet near me had a hut in Batavia that also served St. Charles, Geneva, 
West Chicago, etc. via PON. 

Also a company that built a middle mile / anchor institution fiber network with 
a BTOP grant 12+ years ago convinced the county to let them take it private, 
and they have run aerial fiber in most of Shabbona which is one of the towns 
Mike mentioned. With my misconception about how FTTH is typically deployed, I 
expected there to be at least one cabinet or hut in town. But I think they are 
just using strands from the BTOP project and feeding it passively from a 
distant town. 

I would prefer to see more redundancy, especially since both buried and aerial 
fiber definitely gets damaged around here, but I guess practical results matter 
more than what-ifs. At least local power outages shouldn’t take it down, and a 
central NOC or hut should be able to have serious battery and/or generator 
backup. 



From: AF  On Behalf Of Josh Luthman 
Sent: Saturday, March 16, 2024 4:12 PM 
To: AnimalFarm Microwave Users Group  
Subject: Re: [AFMUG] PON question 


PON is one port at your end and then goes through splitters that reduce light 
and add ports to end up at customer ONTs. 1:128 is pretty short range and high 
customer count - we could never do that in a rural plant (5-15 miles). Maybe 
1:64 but that's about the limit. There is NO redundancy in PON. Best you could 
do is 2x32 or whatever splitters which is where you feed the downstream fiber 
with two PON ports. An engineer from Metronet told me they did that but no one 
could ever answer why (technically or operationally). Think like you have an AP 
on a tower feeding 32 customers. What are the chances you have an AP right 
below it with the same SSID/PSK/frequency for the customers to connect to if 
the first AP goes down? 



Think of Active E like a bunch of dumb switches. You have a 48 port switch that 
goes to 48 customers using 48 fibers. If the fiber feeding the switch goes 
down, it can go to a different fiber/uplink port. 



On Fri, Mar 15, 2024 at 7:59 PM Ken Hohhof < khoh...@kwom.com > wrote: 





Since there are FTTH people here and I’m mostly ignorant of such things, maybe 
someone can clear something up for me. 

I always assumed a PON based FTTH system had a topology kind of like HFC. I 
expected fiber down the street with splitters, but fed by some sort of 
neighborhood node in a cabinet with power and electronics, fed by active EPL 
style fiber. Which could have redundant paths, rings, etc. so a fiber cut 
wouldn’t take down a whole town or multiple towns, the backbone traffic would 
reroute. 

I’ve been told this is not the case. And that instead, each PON could go back 
over a strand to a headend several towns and many miles away, all passive. 

Sorry for the poor description of my question, hopefully you can figure out 
what I’m asking. 
-- 
AF mailing list 
AF@af.afmug.com 
http://af.afmug.com/mailman/listinfo/af_af.afmug.com 


-- 
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AF@af.afmug.com 
http://af.afmug.com/mailman/listinfo/af_af.afmug.com 

-- 
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AF@af.afmug.com
http://af.afmug.com/mailman/listinfo/af_af.afmug.com

Re: [AFMUG] PON question

[Chuck McCown via AF]

IMO PON is nor more or less redundant/robust than old fashioned POTS. 



From: Ken Hohhof 
Sent: Saturday, March 16, 2024 3:39 PM
To: 'AnimalFarm Microwave Users Group' 
Subject: Re: [AFMUG] PON question

Mike Hammett kind of touched on what I was asking and why.  I was told that 
Metronet near me had a hut in Batavia that also served St. Charles, Geneva, 
West Chicago, etc.  via PON.

 

Also a company that built a middle mile / anchor institution fiber network with 
a BTOP grant 12+ years ago convinced the county to let them take it private, 
and they have run aerial fiber in most of Shabbona which is one of the towns 
Mike mentioned.  With my misconception about how FTTH is typically deployed, I 
expected there to be at least one cabinet or hut in town.  But I think they are 
just using strands from the BTOP project and feeding it passively from a 
distant town.

 

I would prefer to see more redundancy, especially since both buried and aerial 
fiber definitely gets damaged around here, but I guess practical results matter 
more than what-ifs.  At least local power outages shouldn’t take it down, and a 
central NOC or hut should be able to have serious battery and/or generator 
backup.

 

 

From: AF  On Behalf Of Josh Luthman
Sent: Saturday, March 16, 2024 4:12 PM
To: AnimalFarm Microwave Users Group 
Subject: Re: [AFMUG] PON question

 

PON is one port at your end and then goes through splitters that reduce light 
and add ports to end up at customer ONTs.  1:128 is pretty short range and high 
customer count - we could never do that in a rural plant (5-15 miles).  Maybe 
1:64 but that's about the limit.  There is NO redundancy in PON.  Best you 
could do is 2x32 or whatever splitters which is where you feed the downstream 
fiber with two PON ports.  An engineer from Metronet told me they did that but 
no one could ever answer why (technically or operationally).   Think like you 
have an AP on a tower feeding 32 customers.  What are the chances you have an 
AP right below it with the same SSID/PSK/frequency for the customers to connect 
to if the first AP goes down?

 

Think of Active E like a bunch of dumb switches.  You have a 48 port switch 
that goes to 48 customers using 48 fibers.  If the fiber feeding the switch 
goes down, it can go to a different fiber/uplink port.

 

On Fri, Mar 15, 2024 at 7:59 PM Ken Hohhof  wrote:

  Since there are FTTH people here and I’m mostly ignorant of such things, 
maybe someone can clear something up for me.

   

  I always assumed a PON based FTTH system had a topology kind of like HFC.  I 
expected fiber down the street with splitters, but fed by some sort of 
neighborhood node in a cabinet with power and electronics, fed by active EPL 
style fiber.  Which could have redundant paths, rings, etc. so a fiber cut 
wouldn’t take down a whole town or multiple towns, the backbone traffic would 
reroute.

   

  I’ve been told this is not the case.  And that instead, each PON could go 
back over a strand to a headend several towns and many miles away, all passive.

   

  Sorry for the poor description of my question, hopefully you can figure out 
what I’m asking.

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Re: [AFMUG] PON question

[Ken Hohhof]

Mike Hammett kind of touched on what I was asking and why.  I was told that 
Metronet near me had a hut in Batavia that also served St. Charles, Geneva, 
West Chicago, etc.  via PON.

 

Also a company that built a middle mile / anchor institution fiber network with 
a BTOP grant 12+ years ago convinced the county to let them take it private, 
and they have run aerial fiber in most of Shabbona which is one of the towns 
Mike mentioned.  With my misconception about how FTTH is typically deployed, I 
expected there to be at least one cabinet or hut in town.  But I think they are 
just using strands from the BTOP project and feeding it passively from a 
distant town.

 

I would prefer to see more redundancy, especially since both buried and aerial 
fiber definitely gets damaged around here, but I guess practical results matter 
more than what-ifs.  At least local power outages shouldn’t take it down, and a 
central NOC or hut should be able to have serious battery and/or generator 
backup.

 

 

From: AF  On Behalf Of Josh Luthman
Sent: Saturday, March 16, 2024 4:12 PM
To: AnimalFarm Microwave Users Group 
Subject: Re: [AFMUG] PON question

 

PON is one port at your end and then goes through splitters that reduce light 
and add ports to end up at customer ONTs.  1:128 is pretty short range and high 
customer count - we could never do that in a rural plant (5-15 miles).  Maybe 
1:64 but that's about the limit.  There is NO redundancy in PON.  Best you 
could do is 2x32 or whatever splitters which is where you feed the downstream 
fiber with two PON ports.  An engineer from Metronet told me they did that but 
no one could ever answer why (technically or operationally).   Think like you 
have an AP on a tower feeding 32 customers.  What are the chances you have an 
AP right below it with the same SSID/PSK/frequency for the customers to connect 
to if the first AP goes down?

 

Think of Active E like a bunch of dumb switches.  You have a 48 port switch 
that goes to 48 customers using 48 fibers.  If the fiber feeding the switch 
goes down, it can go to a different fiber/uplink port.

 

On Fri, Mar 15, 2024 at 7:59 PM Ken Hohhof mailto:khoh...@kwom.com> > wrote:

Since there are FTTH people here and I’m mostly ignorant of such things, maybe 
someone can clear something up for me.

 

I always assumed a PON based FTTH system had a topology kind of like HFC.  I 
expected fiber down the street with splitters, but fed by some sort of 
neighborhood node in a cabinet with power and electronics, fed by active EPL 
style fiber.  Which could have redundant paths, rings, etc. so a fiber cut 
wouldn’t take down a whole town or multiple towns, the backbone traffic would 
reroute.

 

I’ve been told this is not the case.  And that instead, each PON could go back 
over a strand to a headend several towns and many miles away, all passive.

 

Sorry for the poor description of my question, hopefully you can figure out 
what I’m asking.

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Re: [AFMUG] PON question

[Josh Luthman]

PON is one port at your end and then goes through splitters that reduce
light and add ports to end up at customer ONTs.  1:128 is pretty short
range and high customer count - we could never do that in a rural plant
(5-15 miles).  Maybe 1:64 but that's about the limit.  There is NO
redundancy in PON.  Best you could do is 2x32 or whatever splitters which
is where you feed the downstream fiber with two PON ports.  An engineer
from Metronet told me they did that but no one could ever answer why
(technically or operationally).   Think like you have an AP on a tower
feeding 32 customers.  What are the chances you have an AP right below it
with the same SSID/PSK/frequency for the customers to connect to if the
first AP goes down?

Think of Active E like a bunch of dumb switches.  You have a 48 port switch
that goes to 48 customers using 48 fibers.  If the fiber feeding the switch
goes down, it can go to a different fiber/uplink port.

On Fri, Mar 15, 2024 at 7:59 PM Ken Hohhof  wrote:

> Since there are FTTH people here and I’m mostly ignorant of such things,
> maybe someone can clear something up for me.
>
>
>
> I always assumed a PON based FTTH system had a topology kind of like HFC.
> I expected fiber down the street with splitters, but fed by some sort of
> neighborhood node in a cabinet with power and electronics, fed by active
> EPL style fiber.  Which could have redundant paths, rings, etc. so a fiber
> cut wouldn’t take down a whole town or multiple towns, the backbone traffic
> would reroute.
>
>
>
> I’ve been told this is not the case.  And that instead, each PON could go
> back over a strand to a headend several towns and many miles away, all
> passive.
>
>
>
> Sorry for the poor description of my question, hopefully you can figure
> out what I’m asking.
> --
> AF mailing list
> AF@af.afmug.com
> http://af.afmug.com/mailman/listinfo/af_af.afmug.com
>
-- 
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AF@af.afmug.com
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Re: [AFMUG] PON question

[Chuck McCown via AF]

Always nice if you can ring all your remotes/cabinets.  
But you can home run the customers of feed many off of a single strand.  We put 
splitters in splice cases as needed but I put in enough strands to do active 
ethernet if we want.  Very flexible.  If you cut down the the number of splits 
you can reach farther, just like a coaxial network.  However the reach is crazy 
compared to coax.  I have heard of splits as high as 128 per strand.

All of our new stuff is XGS-PON.  Dropped a bunch of money on it and have not 
even used it yet.  


From: Mark Radabaugh 
Sent: Saturday, March 16, 2024 11:04 AM
To: AnimalFarm Microwave Users Group 
Subject: Re: [AFMUG] PON question

XGS-PON can theoretically run at 100km, though 60km is about the practical 
limit we have seen,   With a active cabinet in the center and a 60km reach you 
can have an effective diameter of ~70 miles.   With slack, routing, sag, etc. 
50 miles is a possibility for cabinet spacing. 

In the rural areas we use a 10 mile radius with active cabinets 20 miles apart. 
   The active cabinet feeds unpowered splitters either in splice cases along 
the way, and also feeds passive splitter cabinets in the pockets of density 
(subdivisions, villages, towns).If the density in a village becomes high 
enough (or grows) the passive cabinet can be changed to an active cabinet and 
the fiber previously used to feed splitters becomes your 100G feed into the 
cabinet.   

The cabinets that are 20 miles apart have a ring (well, more of a mesh) feed of 
100G links to them to provide redundancy, but there is no protection for the 
PON customers on the passive side.   There are ways to provide for PON 
redundancy including dual fed PON’s with a live / standby link, but it’s 
significantly more complex to engineer (and IMHO not worth the complexity) 
given the overall reliability and simplicity of GPON.   For a high value 
customer that needs redundancy active fiber is simpler to deal with for 
creating redundancy.

Mark



  On Mar 15, 2024, at 7:57 PM, Ken Hohhof  wrote:

  Since there are FTTH people here and I’m mostly ignorant of such things, 
maybe someone can clear something up for me.
   
  I always assumed a PON based FTTH system had a topology kind of like HFC.  I 
expected fiber down the street with splitters, but fed by some sort of 
neighborhood node in a cabinet with power and electronics, fed by active EPL 
style fiber.  Which could have redundant paths, rings, etc. so a fiber cut 
wouldn’t take down a whole town or multiple towns, the backbone traffic would 
reroute.
   
  I’ve been told this is not the case.  And that instead, each PON could go 
back over a strand to a headend several towns and many miles away, all passive.
   
  Sorry for the poor description of my question, hopefully you can figure out 
what I’m asking.
  -- 
  AF mailing list
  AF@af.afmug.com
  http://af.afmug.com/mailman/listinfo/af_af.afmug.com




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Re: [AFMUG] PON question

[Mark Radabaugh]

XGS-PON can theoretically run at 100km, though 60km is about the practical 
limit we have seen,   With a active cabinet in the center and a 60km reach you 
can have an effective diameter of ~70 miles.   With slack, routing, sag, etc. 
50 miles is a possibility for cabinet spacing.

In the rural areas we use a 10 mile radius with active cabinets 20 miles apart. 
   The active cabinet feeds unpowered splitters either in splice cases along 
the way, and also feeds passive splitter cabinets in the pockets of density 
(subdivisions, villages, towns).If the density in a village becomes high 
enough (or grows) the passive cabinet can be changed to an active cabinet and 
the fiber previously used to feed splitters becomes your 100G feed into the 
cabinet.   

The cabinets that are 20 miles apart have a ring (well, more of a mesh) feed of 
100G links to them to provide redundancy, but there is no protection for the 
PON customers on the passive side.   There are ways to provide for PON 
redundancy including dual fed PON’s with a live / standby link, but it’s 
significantly more complex to engineer (and IMHO not worth the complexity) 
given the overall reliability and simplicity of GPON.   For a high value 
customer that needs redundancy active fiber is simpler to deal with for 
creating redundancy.

Mark

> On Mar 15, 2024, at 7:57 PM, Ken Hohhof  wrote:
> 
> Since there are FTTH people here and I’m mostly ignorant of such things, 
> maybe someone can clear something up for me.
>  
> I always assumed a PON based FTTH system had a topology kind of like HFC.  I 
> expected fiber down the street with splitters, but fed by some sort of 
> neighborhood node in a cabinet with power and electronics, fed by active EPL 
> style fiber.  Which could have redundant paths, rings, etc. so a fiber cut 
> wouldn’t take down a whole town or multiple towns, the backbone traffic would 
> reroute.
>  
> I’ve been told this is not the case.  And that instead, each PON could go 
> back over a strand to a headend several towns and many miles away, all 
> passive.
>  
> Sorry for the poor description of my question, hopefully you can figure out 
> what I’m asking.
> -- 
> AF mailing list
> AF@af.afmug.com 
> http://af.afmug.com/mailman/listinfo/af_af.afmug.com

-- 
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AF@af.afmug.com
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Re: [AFMUG] PON question

[Chris Fabien]

PON is much more flexible mainly due to the much lower signal loss per
distance. There are ways to deploy that almost exactly mirror an HFC
network - There are strand mounted OLTs, you can "tap" the signal in
exactly the same fashion as HFC taps where you have one active coax or
fiber and the tap values change as you go down the road to keep
customer outputs correct. They even make plug and play taps that look
almost like CATV taps.

I think it's more common to have your aggregation points serving
larger areas with PON, mainly because you can and it's more economical
that way. One large cabinet or hut can serve thousands of homes within
a 10-15 mile radius without sacrificing anything. Using splitters out
in the field (small splitter cabinets, or distributed in splice cases)
keeps your PON feeder fiber count moderate so you can hit a huge area
without getting into large cables,cases, and handholes.

In our network, at first we deployed cabinets, but have moved to huts
mainly for security, backup power, cooling, and technician
convenience. It's a rural area so one hut might have two to four
72-288 fibers, but that's a lot of spare strands. Most of our main
runs have at most about 30-40 active PON strands leaving the hut in a
given direction.

On Fri, Mar 15, 2024 at 7:59 PM Ken Hohhof  wrote:
>
> Since there are FTTH people here and I’m mostly ignorant of such things, 
> maybe someone can clear something up for me.
>
>
>
> I always assumed a PON based FTTH system had a topology kind of like HFC.  I 
> expected fiber down the street with splitters, but fed by some sort of 
> neighborhood node in a cabinet with power and electronics, fed by active EPL 
> style fiber.  Which could have redundant paths, rings, etc. so a fiber cut 
> wouldn’t take down a whole town or multiple towns, the backbone traffic would 
> reroute.
>
>
>
> I’ve been told this is not the case.  And that instead, each PON could go 
> back over a strand to a headend several towns and many miles away, all 
> passive.
>
>
>
> Sorry for the poor description of my question, hopefully you can figure out 
> what I’m asking.
>
> --
> AF mailing list
> AF@af.afmug.com
> http://af.afmug.com/mailman/listinfo/af_af.afmug.com

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Re: [AFMUG] PON question

[Mike Hammett]

PON can do either topology you mentioned, assuming vendor support. 


MetroNet uses one hut to feed all of DeKalb, Sycamore, and Cortland. I'm not 
sure if Genoa has their own hut or if they haul back to Sycamore as well. 


In my builds, I want one per town to reduce failure domains. 


I could technically feed PON customers in Shabbona from Hinckley. 




- 
Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 




- Original Message -

From: "Ken Hohhof"  
To: "AnimalFarm Microwave Users Group"  
Sent: Friday, March 15, 2024 6:57:33 PM 
Subject: [AFMUG] PON question 



Since there are FTTH people here and I’m mostly ignorant of such things, maybe 
someone can clear something up for me. 

I always assumed a PON based FTTH system had a topology kind of like HFC. I 
expected fiber down the street with splitters, but fed by some sort of 
neighborhood node in a cabinet with power and electronics, fed by active EPL 
style fiber. Which could have redundant paths, rings, etc. so a fiber cut 
wouldn’t take down a whole town or multiple towns, the backbone traffic would 
reroute. 

I’ve been told this is not the case. And that instead, each PON could go back 
over a strand to a headend several towns and many miles away, all passive. 

Sorry for the poor description of my question, hopefully you can figure out 
what I’m asking. 
-- 
AF mailing list 
AF@af.afmug.com 
http://af.afmug.com/mailman/listinfo/af_af.afmug.com 

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Re: [AFMUG] PON question

[Colin Stanners]

The PON can be split anywhere along the line. The headend OLT can be close
but often is far, usually a cabinet feeding multiple blocks, sometimes a
pile of them in a shed that feeds a whole town or small city. At the OLT
location there will be UPS and usually feed redundancy.



On Fri, Mar 15, 2024, 6:58 p.m. Ken Hohhof  wrote:

> Since there are FTTH people here and I’m mostly ignorant of such things,
> maybe someone can clear something up for me.
>
>
>
> I always assumed a PON based FTTH system had a topology kind of like HFC.
> I expected fiber down the street with splitters, but fed by some sort of
> neighborhood node in a cabinet with power and electronics, fed by active
> EPL style fiber.  Which could have redundant paths, rings, etc. so a fiber
> cut wouldn’t take down a whole town or multiple towns, the backbone traffic
> would reroute.
>
>
>
> I’ve been told this is not the case.  And that instead, each PON could go
> back over a strand to a headend several towns and many miles away, all
> passive.
>
>
>
> Sorry for the poor description of my question, hopefully you can figure
> out what I’m asking.
> --
> AF mailing list
> AF@af.afmug.com
> http://af.afmug.com/mailman/listinfo/af_af.afmug.com
>
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[AFMUG] PON question

[Ken Hohhof]

Since there are FTTH people here and I'm mostly ignorant of such things,
maybe someone can clear something up for me.

 

I always assumed a PON based FTTH system had a topology kind of like HFC.  I
expected fiber down the street with splitters, but fed by some sort of
neighborhood node in a cabinet with power and electronics, fed by active EPL
style fiber.  Which could have redundant paths, rings, etc. so a fiber cut
wouldn't take down a whole town or multiple towns, the backbone traffic
would reroute.

 

I've been told this is not the case.  And that instead, each PON could go
back over a strand to a headend several towns and many miles away, all
passive.

 

Sorry for the poor description of my question, hopefully you can figure out
what I'm asking.

-- 
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