Is anyone else experiencing this issue?: ADSL2 - Fast Downstream, Slow Upstream

Forums › New Zealand Broadband › Is anyone else experiencing this issue?: ADSL2 - Fast Downstream, Slow Upstream

SamF

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#52577 4-Dec-2009 23:51

Hi Everyone,

I am ~200m from the ADSL cabinet that I'm connecting to and until recently I could connect at full ADSL1 speeds (~8mbit/800kbit). My cabinet has recently been upgraded to ADSL2, and I now get ~15mbit download syncs which is great, however, my upload rate has dropped down to 4-500kbits.

Eg:
Downstream Rate:     15216 Kbps
Upstream Rate:     440 Kbps
Downstream Margin:     12 db
Upstream Margin:     13 db
Downstream Line Attenuation:     8
Upstream Line Attenuation:     3

So far i have tried:
Linksys AM300 - Latest Firmware - Low Upload Sync
Netgear DG834G - Latest Firmware - Low Upload Sync
Dynalink ??? (Downer Engineer) - High Upload Sync (which proves my line is not at fault)

Telecom have actually admitted to me that there is a known 'compatibility issue with some modems' due to a problem with the software on the new cabinet equipment. However, they currently seem unwilling to do anything about it which is highly annoying. I have been chasing them for months on this but have received no indication that they are even planning to resolve this at all.

Due to it's nature, it is very likely that many others are also having this problem. So if you are experiencing this issue, please post your sync rates and modem details and I will pass these on to Telecom in order to build a stronger case for all those affected.

Cheers,

Sam.

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#279492 5-Dec-2009 08:43

The new Telecom ISAMs are suited to modems that use Broadcom chipsets (such as the Dynalink) if you want least hassles then use them. The modems supplied by Telecom (Thompsons) are Broadcom based.

TP-Link, DSE, and other brands also sport Broadcom chipsets and at very reasonable prices.

Alcatel (who make the ISAM) currently have about 70% of the worlds DSL ports, so its wise to go with the predomanant supplier of Teleco gear rather than minor brands like Lynksys (who have never made good DSL modems).

Cyril

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SamF

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#279496 5-Dec-2009 09:16

Cheers for the info Cyril. I still think Telecom should pull finger and fix the damn thing tho!

cyril7

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#279497 5-Dec-2009 09:27

There was a similar issue with the new ISAMs recently regarding Huewai modems provided to Vodafone customers (Voda uses Huewai DSLAMs and so provides Huewai modems to both Red network and Telecom wholesale subscribers) where they would not sync over 7.6Mb/s even though they showed they were in ADSL2+ mode.

It appears that during training the two ends of teh system (ISAM and CPE) would incorrectly guide one another to the wrong sync solution as its a two way negotiated protoco, in the end it was the Huewai that was not playing ball, and had to have a firmware change. I also understand that it only effected these modems on certain ISAMs with particular setup configs which vary from cabinet to cabinet depending on cable conditions that cabinet works with. I presume certain cabinets have different profile setups to others, and some of these profiles which effect training protocols did not agree with certain modems.

From my previous post I restate that Alcatel are the largest provider of DSLAM ports worldwide by a country mile, so you may find a bit of a mountain to Muhammad thing happen. So I would first try your modem vendor.

Cyril

SamF

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#279952 7-Dec-2009 11:58

Sure, I'm not disagreeing with you Cyril, I'm in the process of obtaining a Thomson modem now, however, I'm pretty annoyed that I've had to resort to buying a new modem when my perfectly functioning ADSL2+ compatible modem 'isn't compatible' with Telecoms ADSL2 equipment.

Ragnor

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#280212 8-Dec-2009 00:41

Such is life... :)

Fraktul

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#280223 8-Dec-2009 02:03

Arguably you have right to recourse if the device is not fully compliant with the relevent ITU ADSL 2+ standards. Good luck with that however :)

lokeynz

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#281149 10-Dec-2009 11:10

I also noticed this after our exchange was upgraded to ADSL2+

We have 2 dsl connections here and are approx 150m line of sight from the exchange, both connections used to sit on 8mbit down, 800k up with dsl1, now on dsl2 the Telecom connection gets over 900k, Snap gets 400ish.
Both are on Linksys AM300 routers with latest firmware.
I compared these results to a number of our clients and came up with the following:
https://cdn.geekzone.co.nz/imagessubs/a69d942848f741c3c13b7dd22481957a.jpg

Coincidence or sabotage?

I had no luck trying to get this sorted through Snap as Telecom don't recognise this as a fault, best they could do was change the port back to an ADSL1 profile

SamF

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#281203 10-Dec-2009 14:05

Hmmm.. VERY curious!!

I'll pass this info onto my ISP who seems to have at least some limited dialogue going with telecom.

Just so I can pass on clear information, could you please clarify the exact models of the routers in your screenshot collage?

Also, if you could also include an approximate location (or even better, a street name) then this would give telecom no excuses for looking into it in more depth!

It's very interesting that your 2 home connections get different upload speeds! Same modems, same cabinet, different ISPs!! I wonder if there's some back end setting that is set incorrectly for non telecom connections?

Just for arguement's sake, have you tried swapping your 2 AM300s over to confirm that the fault follows the ISP as opposed to the modem? I know they're technically identical, but you never know...

Thanks for sharing that information lockeynz, that will go a long way to strengthening our case!!

lokeynz

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#281213 10-Dec-2009 14:32

I've updated the file with router models and point to point distance from the exchange, i realise phone lines dont travel in a straight line but this will give you some idea of the distances we're working with here.
https://cdn.geekzone.co.nz/imagessubs/1330b6df258dce405906e6bbc542b53e.jpg

I have swapped the 2 AM300's over as well as tried a third AM300 and a D-link DSL-G604T, have tried isolating the line, all with the same results.

If you'd like more specific info on locations of the connections feel free to flick me a pm.

SamF

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#281273 10-Dec-2009 19:02

Awesome, very useful! Thanks lokeynz! I'll pass that info on tonight & keep you posted with any updates. I'll let you know if telecom want any more details.

So just to confirm, on your lines, the AM300 which was going slow on Snap, goes fast on Telecom?

lokeynz

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#281421 11-Dec-2009 10:03

I've swapped the AM300s around this morning and taken screenshots of sync rates before and after, definitely seems to be a bit of difference between the 2 as far as sync rates go but it does still show the slow upstream following the non-telecom connection
https://cdn.geekzone.co.nz/imagessubs/7f05d44fbfea70104dba49e59f363b90.jpg

shadenz

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#281481 11-Dec-2009 13:36

lokeynz: I've swapped the AM300s around this morning and taken screenshots of sync rates before and after, definitely seems to be a bit of difference between the 2 as far as sync rates go but it does still show the slow upstream following the non-telecom connection
https://cdn.geekzone.co.nz/imagessubs/7f05d44fbfea70104dba49e59f363b90.jpg

Hmm interesting, I've been dealing with SamF trying to help out with this fault too - the only thing I can think of is perhaps the Telecom connection is on a different card to the Snap connection?

Could you post up the attenuation on each line to compare ? Is there any chance you could find out through your ISP which port (or even just the card) you're on for each line?

Don't suppose you have a Dynalink/Thompson modem to chuck on the snap line for testing? :)

SamF

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#283891 18-Dec-2009 20:16

Hmm, ok, very odd. Got a Thomson ST536 v6 today and I am regularly achieving 900-950kbits/sec upstream sync rates. Downstream are a little slower by ~1mbit compared to my AM300 which is interesting.

So maybe the Telecom vs Other ISP thing is just a fluke, or Telecom are using older cards for their connections?

richms

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#283895 18-Dec-2009 20:23

Mine has done that many times in the past its a netgear,

It was negotiating ADSL2-RE and getting 128-190 upstream - turning on debug mode and usign some commands I found online for the DG834G (even tho mine isnt that model, as its not wireless and has one port and a USB port to connect to a PC) to lock it into ADSL2+ mode and it always works as it should.

Worth a shot in anycase. Found the details on whirlpool I think.

Richard rich.ms

SamF

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#283897 18-Dec-2009 20:25

I can lock my AM300 into ADSL2 / 2+ mode, but it makes no difference unfortunately :(

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