This is a random question - a friend who lives in a high density residential area has welcomed the introduction of “20 line bundles” of fibre, almost on his door step.
He said he’s going to switch to fibre as soon as possible before they get ‘sold out’ and taken by other residents (there are around 50-70 houses surrounding this new node).
Thing is to my mind, logically they must be easily split up and 20 fibre lines can’t possibly only be for ‘20 houses’…am i wrong? They’d just split them up into however many connections are actually needed surely?
This depends on a lot of things. Who said it, what fibre were they refering to, what country?
Generally, fibre that goes to the cabinet (in UK terms) is usually shared, the fibre it’s self doesn’t really determine how much bandwidth it can take, it depends on the equipment on both ends. 20 fibre lines to the cabinet at 1gbps each would serve lots of people who only buy 100mbps for example.
In the UK most people are still on copper on the last mile so can only get a maximum of 70mbps. Fibre lines at the cabinet will take multiple customers on one fibre line.
It may change slightly (but not much) if it’s fibre to the premises, but the same still kind of applies depending on the equipment in the cabinet.
I’m not a network engineer but I have played one at multiple jobs…
Whenever I have run fiber there were always two different types, one was the main line that ran long distance from router to router, then there were the shorter links that ran to the individual computers or sub-stations. Basically I have run both fiber direct to the server (or in some cases workstations) or to a fiber to copper switch or router (I have done both).
So short answer based on my relatively limited and outdated knowledge (it’s been about 5 years since I worked with fiber), they are probably going to put in a switch at the point where fiber came into the area, and maybe a breakout to groups of houses with copper for the last bit.
typical home broadband over fiber is deployed using something called gpon, this is different from traditional ethernet over fiber
GPON (in its many variants) enables a bunch of residences to share a single fiber.
ISP would hookup a device called the OLT on one end, and then a few kilometers away, there’s be a passive optical splitter (or several) and users would connect ONT/ONU on their side. There’s a protocol that allows and OLT to distribute configuration to ONT/ONUs and that then determines which ont/onu gets to access the shared fiber when.
GPON is actually 2.5Gbps down over one wavelength, and 1.25 Gbps up over another, … commonly it’s deployed such that 32 residences get to share a fiber.
There’s an upgrade path to 10G-PON (10G down 2.5G up in aggregate over fiber), few ISPs are deploying 10G (they can still sell up-to 1Gbps speeds with regular GPON for home use and get away with it)
20 is a weird number, typically you’d get 24 or 96 strands in a cable.
Traditional, cheap and simple Ethernet over fiber is quite different.
It would actually use 2 fibers, one for each direction, and those 2 fibers would be dedicated to that one point-to-point link. Your bandwidth would depend on equipment installed at either end.
There’s a topology using things like OADMs (metro ring networks typically used to use or still use this in a couple of places) . OADM are kind of like filters / multiplexers that allow sharing of fiber to happen by virtue of different users using different wavelengths.
OADM or dedicated fiber lines would typically not be deployed for residential use.
Thank you everyone for your invaluable comments, I really really do appreciate you taking the time to respond.
I should have mentioned this is a UK based question, but again, I’m very grateful. I’m going to report back to my friend and assure him that 20 is not the number of available Fibre connections!
