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Confusing words used to describe speed.

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jehu44
Chat Champion

Having read quite a few threads recently about slow internet speeds I think many customers are as confused as I am about the terms used by technical experts when talking about internet speed.

The term often used by the OCEs is "sync speed". Yet "sync speed" is not a term used in any of the 3 different routers supplied to me by Talktalk. There's "upstream line rate", "downstream line rate", "Maximum upstream line rate" and "maximum downstream line rate". Is "sync speed" any of these or something different? When Talktalk guarantees a minimum download speed is this the "downstream line rate" or the "maximum downstream line rate". Why is the "maximum downstream rate" so much faster than the "downstream line rate"?

 

 

Gondola
Community Star
Solution

Hi @jehu44

 

Here's the advice about 'Sync Speed'.

Here's the advice about the Broadband Code of Conduct agreed with Ofcom.

 

I guess you have been supplied with an HG635 or HG633 router.  Sync Speed is the Downstream Line Rate.  The Maximum Downstream Line Rate is the speed the equipment at the sending end, i.e. the telephone exchange or street cabinet is capable of working at on your line.

 

I see you may also be testing a DSL-3782 router. Sync speed is shown on the DSL page as the DownLink Data Rate.

 

I hope this is the answer you are looking for.

 Gondola - Community support team *

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jehu44
Chat Champion
Thank you Gondola. I think it is inevitably confusing to have so many different terms for the same thing. The link you kindly provided gave "access line speed" as well as
So is it correct to say that a large difference between the maximum download speed (ADSL) and the sync speed is caused by the distance between the cabinet and the customer and/or the distance between the exchange and the customer?
Gondola
Community Star

Yes, very confusing.

 

Ofcom defined the access line speed or 'sync speed' which is the broadband speed at the end of the line (at the Master socket test socket) as it enters your home so does depend on the length of line from the exchange or cabinet, that line's physical characteristics and impairments that require corrections to be applied. 

 

Then to add to the confusion you've got throughput speed or speed checker speed result which is the speed you see at your devices / computers.

 Gondola - Community support team *

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jehu44
Chat Champion

Thanks Gondola

 

One final question. If I am getting very slow ADSL sync speed because of the length and quality of the line from the cabinet, what would be the point of upgrading to fibre? If I tried fibre and found that the speed was still poor, what would Talktalk do then? Keep taking my money or let me revert to the ADSL price? Sorry that's three questions, but I will not ask any more, I promise.

Gondola
Community Star

Hi @jehu44

 

For ADSL your broadband comes all the way from the telephone exchange on a metallic line. 

ADSL-adsl2-speed-against-distance.pngADSL Speed versus distance chart

If that line were perfect and you were, say, 4km or so from the exchange you'd have a broadband downstream speed of around 3Mbps.

 

A fibre to the cabinet (FTTC) connection takes the broadband in an optical fibre from the exchange to a street cabinet that is closer to your home.  Then the metallic line carries the broadband from the street cabinet to your home.

 

80Mbps FTTC Distance vs Speed.jpgFTTC Distance versus speed

If the street cabinet is, say, only 1km from your home and the metallic line from the street cabinet is good then the downstream speed would be around 30Mbps or 10 times better.

 

But it all depends on distance and the quality of the line.  Entry level fibre is capped at 40Mbps downstream at the street cabinet.  The chart above shows what a fibre speed boost of 80Mbps at the street cabinet would provide at various distances between cabinet and your home.

 

When you come to consider a fibre connection then before you buy you'll be given a speed range for the line and a minimum guaranteed speed.  It's at that point that you decide if the speed improvement is worth the extra monthly rental.  My advice is to be pessimistic and say "would it be worth it if I only got the minimum guaranteed speed".

 

There is always a cost outgoing from TalkTalk to Openreach to provision a fibre to the cabinet VDSL connection and with downgrading a connection to ADSL.  These costs cannot be recovered so you need to make the decision based on the point of sale speed figures. 

 Gondola - Community support team *

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martswain
Insightful One
You can also search for the estimated fibre speed for your property on the BT website.
Google is your friend !
Martin
jehu44
Chat Champion

Gondola - Excellent info, thank you. I would mark as best answer but I cannot see the usual button.

jehu44
Chat Champion

Thank you Martin. I'll have a look.