Line Attenuation/SNR Implications

Quin_Dub

Questions for the very technical amongst you.

Just got fixed line broadband setup at home for the first time with Sky.

They have set me up with a 3Mb download profile - I'm connected to a rural exchange and I'm ~4Km from it so I wasn't expecting very much more.

However - When I look at the stats on the router I see that the line is reporting Line Attenuation of 39.5dB and a SNR of between 15dB and 18dB

From what I've read that would seem to suggest that the line should be able to handle a higher throughput than the currently configured 3072kbps. (39dB would seem to suggest that something in the 8Mb-10Mb range might be feasible)

Sky Tech Support say no however - What I'm getting is the max available.

The service I've got is very stable and consistent - It doesn't seem to drop to lower speeds at all regardless of day/time.

So - Are Sky giving me accurate info or are they being Super conservative?

Or are there other factors that would impact the performance??

Thanks in advance

bealtine

With those figures you should theoretically get about 7-9Mbs.

It's likely that the backhaul in the exchange hasn't been updated so the 3Mb profile would be "right" for an almost abandoned exchange

Quin_Dub

bealtine wrote: »

With those figures you should theoretically get about 7-9Mbs.

It's likely that the backhaul in the exchange hasn't been updated so the 3Mb profile would be "right" for an almost abandoned exchange

Thanks for that.

So when you say "Backhaul hasn't been updated" are you talking about the physical hardware or a configuration setting?

The exchange I'm on was enabled about 2 yrs ago , but is not on any of the lists for Next Gen or Fibre so "abandoned" might be the right word...:(

Nonoperational

The backhaul is the exchanges physical connection to the internet. All the lines in the area go to the exchange, and then there is an exchange connection to the internet. You could be on a 10 Mbit connection but if the backhaul from the exchange to the internet is only 5 then that's all your going to get.

Some rural exchanges have unbelievably poor backhaul. Because of this they can't offer higher speeds regardless of how good your line is.

Quin_Dub

Nonoperational wrote: »

The backhaul is the exchanges physical connection to the internet. All the lines in the area go to the exchange, and then there is an exchange connection to the internet. You could be on a 10 Mbit connection but if the backhaul from the exchange to the internet is only 5 then that's all your going to get.

Some rural exchanges have unbelievably poor backhaul. Because of this they can't offer higher speeds regardless of how good your line is.

That makes total sense - Given that, as I said above, the exchange is not included in any of the lists on Eircoms site for upgrades of any sort guess I'll be limited to whatever the backhaul is today for the foreseeable...

Nonoperational

Unfortunately that's probably the case.

airuser

May be some one could answer this for me.

Went to Sky on 14th December, connection speed 8.142 and obtained 7.1/7.3 a 10% increase on VF

Was away from the computer until 2 Jan 2013 all fine no problems.

Line Details Connection 8.142 Attenuation 31.5dB S/n 6dB downstream. Upstream 15 dB S/n 13.13 dB

Sky called saying that my line should be much better and then tested the line. Now, my problems started.

Line Details Connection 4.487 Attenuation 42 dB S/n 6.6dB downstream. Upstream 19.5dB S/n 10.10 dB

One may reboot the Hub and get connection speed varying from 4.1 up to 4.9 M but the stats on the downstream will slightly. Upstream remain constant

Sky spoke to me last week and informed me that they would send out and Engineer to check my system (still waiting). Nothing has changed this side

the front door since I installed Sky. However, when Sky started testing my line the connection speeds dropped.

Any comments

airuser

On BTW on my figures my house has moved 700 m. from the exchange since December 2012

My Exchange is one of Eircom's most up to date and has BT Equipment installed as well. Had the same problems when Vodafone took over BT. Speeds dropped and after several months came up to 6.78M on 8M on.

Airuser

airuser

My line attenuation problem may have been solved. Took all the wiring apart from the master socket to the hub and found a carpet track with picks had gone through the cable. Replaced the cable and the attenuation is back to what it was. However, the speed is still down. Sky are asking an Engineer to call and have a look at the master socket and cables going to and from it.

Sky say they have checked the exchange twice and see no problem there.

Let us see what happens.