ADSL 2mbps running at max 1.75mbps

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SAdata

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Hi. I just got a 2mbps ADSL line. The max speed I can ever get is 1.75mbps on speedtest and downloads at 225KB/s.

If it is 2mbps why does it not run at 2mbps! My router page says the max possible sync speed is 19 odd mbps so its clearly not a distance issue. The line is through Afrihost and I read a ridiculous statement on mybb the other day that Afrihost said to a client that the line is 80/100 - 80% of the 2mbps speed is for download (1.6mps) while the other 20% is for upload - I don't know how true this is!?
 
It has to do with the overhead on the ADSL network. There is quite a detailed explanation available here - http://pflog.net/dsl_overhead/

The 80/20 thing is, well, something Afrihost will need to confirm. That's not how it works with us.
 
SAdata said:
Hi. I just got a 2mbps ADSL line. The max speed I can ever get is 1.75mbps on speedtest and downloads at 225KB/s.

If it is 2mbps why does it not run at 2mbps! My router page says the max possible sync speed is 19 odd mbps so its clearly not a distance issue. The line is through Afrihost and I read a ridiculous statement on mybb the other day that Afrihost said to a client that the line is 80/100 - 80% of the 2mbps speed is for download (1.6mps) while the other 20% is for upload - I don't know how true this is!?
Click to expand...

DSL and TCP Overheads. You'll always lose about 15% regardless of what speed you are on.

http://pflog.net/dsl_overhead/
 
Ah I see! thanks so much :) would other services like 3G and fibre suffer the same fate or is it specific to ADSL
 
SAdata said:
Ah I see! thanks so much :) would other services like 3G and fibre suffer the same fate or is it specific to ADSL
Click to expand...

All network technologies have overheads, some more, some less.

VDSL for instance has a lot smaller overhead than ADSL, so a 40Mbps VDSL line will hit 38Mbps easy, while an ADSL line if it could run at 40Mbps would only hit around 34-35Mbps (ADSL can only go up to 24Mbps)
 
Line Tax dude :p



Lol ok it's just traffic transmission overheads which are necessary for moving those 0s & 1s across the internets
 
what is an acceptable amount of overhead for an 8mb line?
I sync at 7.8mb, but speedtests give me about 4.5, doesnt seem kosher
 
crudler said:
what is an acceptable amount of overhead for an 8mb line?
I sync at 7.8mb, but speedtests give me about 4.5, doesnt seem kosher
Click to expand...

Your speedtest on 8Mbps should be around 6.5Mbps or so.


I'm syncing on 8Mbps now and I get ~ 780 to 800 KB/s.
 
My max line speed is 4Mb, yet I can download at ~960KB/sec. Dunno how that is possible.
 
froot said:
Your speedtest on 8Mbps should be around 6.5Mbps or so.


I'm syncing on 8Mbps now and I get ~ 780 to 800 KB/s.
Click to expand...

so confirms mu suspicions, something is certainly not kosher. I assume once I am syncing at 8 it is no longer a telkom issue, there part is done. And Axxess reckon they are good as well. So can I assume it has to be something internal? Router or wifi giving *** etc (note - only my cell is on the network when i test so it rules out rogue spamware etc, also i have tested with telkom guest account, same speeds)
 
also can changing my MTU have any affect on this.
or vci, vpi, etc
 
crudler said:
also can changing my MTU have any affect on this.
or vci, vpi, etc
Click to expand...

MTU won't affect it. It may affect stability and the ability to sync however (so it should usually be left at around 1492 iirc).
If you change your VCI/VPI you won't be able to connect at all, as our systems work on 8/35.
 
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