Adsl2+ Sync Speed

michaelsblood, May 1, 5:40am
So i finally got slingshot to get a tech out to upgrade my connection to adsl2+ , after telling them several times that the exchange im connected to has been adsl2+ upgraded.

However im only getting slightly higher sync speeds . The modem used to sync at around 7900 - 8000 with adsl1 , and now with adsl2+ syncs at 8155 every time with no variation. Iv tryed unplugging everything but the modem with no difference still syncs at 8155 . Seems like its some how locked at that speed. My Down stream attenuation is 22db and SNR margin is 15db and im approx 900m away from the exchange following the road. From what iv found on the net this should be good for around a 15000 - 19000 sync speed.

So is it possible the sync speed has some how been locked at the exchange? Seems odd that it syncs at exactly the same speed every time. Im in the process of getting another modem to try.

swivel, May 1, 5:54am
Whats the modem you have ??

michaelsblood, May 1, 5:56am
Dlink DSL504T

baker-assoc, May 1, 5:58am
Get a new ADSL2 Capable Modem.

advcomp, May 1, 5:59am
lol its the copper wire to your place thay cant handel much

baker-assoc, May 1, 6:00am
If they are syncing at 8155 on ADSL1 there copper is more than good enough to get ADSL2

michaelsblood, May 1, 6:01am
The modem is adsl2+ capable. And i know of lots of people on copper fairly close to the exchange with 15000+ sync speeds.

michaelsblood, May 1, 6:03am
Im trying to borrow a friends modem to see whats up ,if that syncs at exactly 8155 somethings up.

skyline_guy_r34, May 1, 6:18am
Your attenuation and SNR seem fairly high.

I have 13db attentuation and 9db SNR on adsl2. Not sure how far from the exchange, and my sync speed is showing at just over 14000. With more resistance going through your line as Attenuation and SNR represent compared to me, 8000 seems ok.

kane199, May 1, 6:22am
Firmware update perhaps? is the modem set to ADSL2+ in the settings?

michaelsblood, May 1, 6:23am
But i mean i was almost maxing the adsl1 sync speed . So with adsl2+ i would expect an improvement of more then 155kb/s

michaelsblood, May 1, 6:25am
Its set to multi-mode. But yes iv tried setting to adsl2+ manually and get thesame sync speed. Iv also tried the dlink firmware with same result . Im currently running routertech firmware which is much better then the shitty dlink firmware.

lostdude, May 1, 6:27am
As Kane said, is modulation set to ADSL2+ on the modem?

michaelsblood, May 1, 6:28am
As far as i was aware the higher the SNR the Better. and the lower the attenuation the better.

skyline_guy_r34, May 1, 6:35am
SNR and attenuation you want both to be as low as possible. The magic number for SNR is 6db. And it increases in increments of 3db. Each increase of 3db over the 6db figure can result in 500-750kbps less in sync speed.

michaelsblood, May 1, 6:43am
well the modem reports SNR margin .. And this is what i understood that to be (taken from a website ,it explains it far better then i could)....

The SNR Margin is the difference between the actual SNR and the SNR required to run at a given speed. For example, if you need 20dB of SNR to run at 512Kbps, and the actual line SNR is 45dB, then the SNR Margin is 25dB.

"The SNR is the signal-to-noise ratio. It is the ratio between the strength of the signal and the background noise on the line and is universally expressed as a logarithmic ratio (decibels or dB). For a given line the SNR remains essentially fixed whatever the speed you are running.

ADSL routers and modems actually report the SNR Margin, and the term used to describe this varies but is generally ???SNR Margin???, ???Noise Margin???, ???Margin???, ???Receive Margin???.

The SNR Margin is the difference between the actual SNR and the SNR required to run at a given speed. For example, if you need 20dB of SNR to run at 512Kbps, and the actual line SNR is 45dB, then the SNR Margin is 25dB.

The main reason why SNR margins fall as the line speed increases is that the required SNR increases. For example, if increasing the speed from 512Kbps to 2MBps raises the required SNR from 20db to 30dB then the margin left will fall from 25dB to 15dB (as 45dB-30dB = 15dB.) "

michaelsblood, May 1, 7:32am
Even the router expects better .. haha

I dont know? iv had faults since i got broadband at my current address 2 faulty ports apparently up at the exchange.maybe im still being limited to adsl1 spec even though im connecting with the adsl2 signal. Ill ask a chorus tech if i see one come into work tomorrow.

gyrogearloose, May 1, 7:42am
I agree, I had a Vodafone supplied Huawai that was less than 2 years old, wouldn't go faster than about 8 although it should have, changed to a new TP-link and now it's 15mbps...

smac, May 1, 9:07am
Said it before, many supposed ADSL2 modems for sale in NZ use a chipset that does not play well with the NZ cabinets. They will give a max sync rate at about what you are seeing, and no change in settings will improve it. The one I had with this problem was a linksys AG300 but there's others. There's a couple of users on geekzone that will be able to tell you if yours is one of the problem ones.

cjdnzl, May 1, 9:11am
Something wrong there.SNR - signal-to-noise ratio - should be at least 6dB, and the higher the better.The higher the ratio, the less any noise can interfere with the wanted signal.Noise is not good, the aim is to have minimal noise and maximal signal, i.e. a large SNR.Also, dB ratios are not limited to 3 dB steps, I don't know where you got that idea from, you can have even fractional dB ratios if you want.

peter148, May 1, 9:18am
Some of those old ADSL2+ capable modems will only work at ADSL2+ speed once you have updated the firmware.

johnf_456, May 1, 9:31am

johnf_456, May 1, 9:33am

hybridtheory1, May 1, 9:55am
SNR standards in NZ is set to 8db. UK is I think 6db. Higher the better, to an extent.

Reason why you're getting slow connect rates is probably the Alcatel Mini ISAM/ISAM is still configured to a Lower Power port profile. You can ring up your ISP and get them to bump it up, however if the cabling isnt up to scratch, you will get issues, eg dsl bouncing, or no sync. Hopefully you're not in an area where they have .32mm cabling. .40 is borderline, but .5 is ideal, or the thicker. Also check for any laterals in your house(phone jacks with cable plugged in but no telephone. Creates reflections which can contribute.

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