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manuetdeo

join:2012-01-04
Sun City, CA

upload speeds

i was just wondering if anyone know why the upload speeds are always less that the download speeds? don't they go both ways? why is it 50/25 or 75/35 or 150/65? just asking?



birdfeedr
Premium,MVM
join:2001-08-11
Warwick, RI
kudos:9

Because the way BPON, GPON and XGPON are designed is the aggregate download speeds on the PON cards are higher than the upload speeds. Those are divided by the number of splits on the fiber, usually 16 or 32.

Actually, that's the same reason cable is the same way. There's more total download available than upload. Cable splits it out at a higher ratio. 100 or higher.


ScrawnyB

join:2004-05-18
Carlisle, PA
kudos:1

Yes, like this:

Source: »Verizon Online FiOS FAQ »What is BPON or GPON?

quote:
What is BPON or GPON?
BPON: Broadband Passive Optical Network
GPON: Gigabit Passive Optical Network

FiOS networks are built upon Passive Optical Networks.

BPON conforms to the ITU-T G983.1 specification which is capable of 622 Mbps download and 155 Mbps upload. Each BPON fiber is split using an optical splitter to serve 16 or 32 users.

GPON conforms to the ITU-T G984.1 specification. Verizon's GPON implementation uses Gig-E instead of ATM that was used with BPON. A 2.4 Gbps download speed coupled with a 1.2 Gbps upload speed. Each GPON fiber is split to serve 16 or typically 32 users. Verizon's next phase of GPON will support 64 users per fiber.

Verizon is building new networks with GPON technology, while existing BPON systems will only be upgraded when capacity limits are reached.



bigdaddy

join:2009-11-18
kudos:2
reply to manuetdeo

BPON split 32 way's 19.4375Mbps download and 4.84375Mbps upload per user.

GPON split 32 way's 77.75Mbps Download and 38.875Mbps upload per user.

XG-PON split 32 way's 312.5Mbps download and 78.125Mbps upload per user.

FiOS Quantum user's need to be Upgraded to XG-PON to prevent Over Subscription Problem's down the road. Especially those on the 150/65Mbps and 300/65Mbps tiers. That way all users can be Guaranteed there level of speed.


lijacobs

join:2010-07-30
Lawrence, NY
kudos:1
Reviews:
·Verizon FiOS

said by bigdaddy:

FiOS Quantum user's need to be Upgraded to XG-PON to prevent Over Subscription Problem's down the road. Especially those on the 150/65Mbps and 300/65Mbps tiers. That way all users can be Guaranteed there level of speed.

The vast majority of FiOS subscribers use their service to surf the web and check their email. There is no over subscribtion problem now or down the road for quite some time.


Vamp
5c077
Premium
join:2003-01-28
MD
kudos:1

said by lijacobs:

said by bigdaddy:

FiOS Quantum user's need to be Upgraded to XG-PON to prevent Over Subscription Problem's down the road. Especially those on the 150/65Mbps and 300/65Mbps tiers. That way all users can be Guaranteed there level of speed.

The vast majority of FiOS subscribers use their service to surf the web and check their email. There is no over subscribtion problem now or down the road for quite some time.

That's what they said when they built the interstate system , now look at traffic near major cities, 2mph during rush hours.
--
75/35 FIOS || MSN Msgr: scott001^gmail_com

McBane

join:2008-08-22
Plano, TX
reply to lijacobs

That is very dependent on what area you live in. Netflix streaming, torrents, gaming. If you live in an area with a high concentration of tech workers like me it's a lot more than just surfing the web and checking email.


serge87

join:2009-11-29
reply to manuetdeo

I'll believe all this over-subscription hysteria when I finally see some hard data


lijacobs

join:2010-07-30
Lawrence, NY
kudos:1
Reviews:
·Verizon FiOS
reply to McBane

said by McBane:

That is very dependent on what area you live in. Netflix streaming, torrents, gaming. If you live in an area with a high concentration of tech workers like me it's a lot more than just surfing the web and checking email.

We've had this discussion before and as I said before the readers of this discussion group are not typical. I live in an upscale neighborhood on Long Island, NY (myself not included) and most of the users are as I described. The vast majority of the customers in the in the FiOS footprint are as I described. Many of the homes I visit here still have analog, CRT tv's and five to ten year old computers. Over subscribtion is not and won't be a problem except in very isolated areas.

manuetdeo

join:2012-01-04
Sun City, CA
reply to manuetdeo

So the equipment is designed that way because they figure we would never upload that much?
So if a business wants to maximize their upload speed or gamers want the lowest latency(which i'm assuming you get by the fastest speeds) you have to get the fastest download you can even if you don't use it?


pittpete1

join:2009-06-12
Reviews:
·Frontier Communi..

said by manuetdeo:or gamers want the lowest latency(which i'm assuming you get by the fastest speeds) you have to get the fastest download you can even if you don't use it?
[/BQUOTE :

Not necessarily true
»compnetworking.about.com/od/spee···peed.htm


cramer
Premium
join:2007-04-10
Raleigh, NC
kudos:9
reply to bigdaddy

PONs are split in the upstream direction. Because each CPE cannot see the others, the transmitter must be assigned a precise time period where it can use the fibre without stepping on anyone. Downstream is one-to-many... every CPE sees the same thing -- the payload is encrypted so there's no worry of anyone seeing anyone else's traffic.

The asymmetric nature of internet speeds is a holdover from earlier days when usage was highly asymmetric -- fetching a web page, for example, transmits a small request and gets a voluminous response. Then various technologies were designed exploiting that asymmetric nature -- analog modems, ADSL, DOCSIS, etc. PONs are no different here... there's a finite upstream spectrum that has to be evenly and predictably divided.

[Note: looking at the 4wk totals from my office... we're almost symmetric... 650MB more up than down. Uploading VM images to cloud hosting really skews the average.]


manuetdeo

join:2012-01-04
Sun City, CA

that makes sense


batsona
Maryland

join:2004-04-17
Ellicott City, MD
Reviews:
·Vonage
·Verizon FiOS
reply to manuetdeo

Is the OP asking why speeds are asynchronous? (higher downstream than upstream)?

If so: When you look at the average TCP conversation between websites & their clients, there is 'usually' more traffic moving downstream to the client than there is moving the other direction. So, the traffic amounts seem lop-sided. Most all carriers cater their offerings to match this. Instead of offering a 35/35 service, they might offer 35/15, or something like that. This way, that bandwidth that they're not giving you on the upstream can be allocated across other customers, or allocated elsewhere etc etc....

Sure, carriers also offer synchronous service too, for those who want it and will pay for it.

it's just a matter of the most 'efficient' allocation of bandwith that still meets the customers' needs.