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Standard User deleted
(deleted) Tue 26-Oct-10 22:42:53
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Low sync speed for my line attenuation?


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Hi.
I've just moved from ADSLmax to a resold Opal LLU service.
On ADSL max my stats for downstream would typically be
Att 19db
Snr 11db
Sync 8128 kbps

Now on ADSL2+ I am getting the following:
Att 20db
Snr 12db
Sync 12559 kbps

Taking into account I am currently on a target noise margin of 12db with interleaving on does this seem like a low sync speed?
Looking at other comments on the boards here and using the Kitz max speed estimator I would have expected around 20000kbps at 6 db or 18000kbps at 12db.

Currently using a Zyxel 660R 61C and the snr has been rock steady at 12db.

Thanks
Gary
Administrator MrSaffron
(staff) Tue 26-Oct-10 23:04:47
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Re: Low sync speed for my line attenuation?


[re: deleted] [link to this post]
 
Yeap looks low - the 12db SNR is not helping possibly.

Check with Opal that they are not running a DLM profiling system.

Also do the stats vary at all if using your test socket

Andrew Ferguson, [email protected]
www.thinkbroadband.com - formerly known as ADSLguide.org.uk
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User deleted
(deleted) Tue 26-Oct-10 23:41:50
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Re: Low sync speed for my line attenuation?


[re: MrSaffron] [link to this post]
 
Thanks.
Ill phone up tomorrow and ask to be put on a 6db profile.
Hadn't realised it's possible that the sync rate could be held back.
I'll ask Vivaciti about that too.

Is it possible that the modem could also be holding the sync rate back and that a change here could also improve things?

I have seen a sync around 14000 in the test socket but just tried it now and sync dropped slightly to 11800. Att dropped to 18db.


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Standard User tommy45
(experienced) Tue 26-Oct-10 23:55:42
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Re: Low sync speed for my line attenuation?


[re: deleted] [link to this post]
 
It may also be capped at a certain speed by default, in which case once uncapped the available snr would increase leading to an automatic increase in sync at the 12db, even more if on a 6db or a 3db, but as suggested choosing the most compatible router can also make a big difference it down to chipsets they use,being a near match with the exchange kit, my line if i use a broadcom or alcatel based router i get a lower sync than if i use a conexant based router, as the dslam is similar a chip, but if used it on o2/be it would not perform as good, as their chipsets are broadcom based

Standard User deleted
(deleted) Wed 27-Oct-10 23:52:29
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Re: Low sync speed for my line attenuation?


[re: tommy45] [link to this post]
 
Requested a change to 6db today with interleaving switched off which was completed nice and quickly smile

Initially synced at 16400kbps at 6db margin. After fitting a filtered faceplate the sync dropped to 15400 but att dropped to 18db from 20db.

Still seems around 4000 short but I'll see how it goes.

Was told that any DLM is removed if a change to margin/interleaving is requested which implies there may have been some on the line before.

Going to try a speedtouch 516v6 tomorrow to see if that makes a difference over the zyxel 660r 61c.

Gary
Standard User deleted
(deleted) Sat 30-Oct-10 10:44:16
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Re: Low sync speed for my line attenuation?


[re: deleted] [link to this post]
 
Well the speedtouch synced at 17500 so a nice improvement.
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