FTTH Vs DSL : Symmetric Data Transfers Discussion

@thebigk • Sep 25, 2024

Sep 25, 2024

991

Pardon my limited knowledge of the networks; but in my quest of finding out differences between DSL connections and FTTH connections; the most important point that struck me is that fiber connections are symmetric. This means, the upload speeds and download speeds are different with the former being significantly lesser than the later. But in fiber connections (FTTH), the data transfers are symmetric, meaning upload and download speeds are the same. That brings me to following questions -

Does a 16 Mbps line mean : 16 Mbps upload/download at the same time OR 8 Mbps upload/download simultaneously?
What makes fibers be symmetric and why can't DSLs be symmetric?
What's the cap on DSL data transfers? Some say it's limited while others say it's unlimited. Is the data that can be transferred through a copper cable a direct function of the overall current passing through it?

Looking forward to answers / pointers.

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vinod1993

@vinod1993-r3yTlk • Sep 7, 2012

I think I can answer some of your questions. DSL is generally known as ADSL(Asymmetric digital subscriber line) provided by copper lines which means that more bandwidth is given for downlink and lesser bandwidth for uplink(8Mbps,2Mbps respectively,for example) whereas FTTH provides symmetric speed. Yes, I suppose 16 Mbps line mean 16 Mbps upload/download at the same time. In my opinion as Fiber cables are used in FTTH it's more expensive than a DSL line(comparatively cheaper). Symmetric DSL's are available. There's something called SDSL(Symmetric digital subscriber line) which facilitates symmetric transfer but I don't think it's widely used for residential purposes. You need a SDSL router to use it. It costs around Rs.3000(a rough estimate,may vary but not a lot) per month for a 512k/512k SDSL line. There's also something called symmetrically speeded ADSL which provides good symmetry. From some of my references I found out that unless ADSL2+(with upload speeds cable of 1Mbit) is available in your area, there's no point in using a symmetric DSL connection. 😀

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Abhishek Rawal

@abhishek-fg9tRh • Sep 8, 2012

SDSL is available, its only drawback that i know is that; the landline connection stops working when SDSL is in use.
The cap of adsl is 50 Mbps.
hdsl and vdsl has huge cap value, but very costly; hence not consumer friendly.
I would prefer using FOCs than selecting costly routers which uses cheapass transmission line.
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vinod1993

@vinod1993-r3yTlk • Sep 8, 2012

Caps on data transfers can be either limited or unlimited,it depends.
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Abhishek Rawal

@abhishek-fg9tRh • Sep 8, 2012

we are not talking about "data transfer" here; we are elaborating "data transfer RATE".
Both are totally different terms.

data transfer is total amt of data transfered in specific interval of time(eg. 5 GB transferred in 2 hrs) while suffix "RATE" means downlink/uplink speed.(eg 5 GB transferred in 20 minutes at rate of 5 MBps)

There no such thing as unlimited data transfer rate, everything has it's limit. In DSL more the distance from NIT, more the bandwidth loss and less is transfer rate achieved (major drawback); while in FOCs very less loss is obtained, hence distance between transmitter(isp) and reciever(consumer) is not a major concern.
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vinod1993

@vinod1993-r3yTlk • Sep 8, 2012

Troll_So_Hard
we are not talking about "data transfer" here; we are elaborating "data transfer RATE".
Both are totally different terms.

data transfer is total amt of data transfered in specific interval of time(eg. 5 GB transferred in 2 hrs) while suffix "RATE" means downlink/uplink speed.(eg 5 GB transferred in 20 minutes at rate of 5 MBps)

There no such thing as unlimited data transfer rate, everything has it's limit. In DSL more the distance from NIT, more the bandwidth loss and less is transfer rate achieved (major drawback); while in FOCs very less loss is obtained, hence distance between transmitter(isp) and reciever(consumer) is not a major concern.
I am not talking about the cap on bandwith,but the cap on data transfer. What you say is generally called as "bit cap" but I was talking about "data cap". I suppose #-Link-Snipped-# asked about the "data cap". 😀

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