Talktalk LLU sync speeds

We've just transferred over to a talktalk (business) LLU connection. The modem figures we now have are:

Downstream Rate: 6967 Kbps
Upstream Rate: 899 Kbps
Downstream Margin: 13 db
Upstream Margin: 11 db
Downstream Line Attenuation: 35
Upstream Line Attenuation: 38
Downstream Transmit Power: 19
Upstream Transmit Power: 12
LOS Errors: 1


Should we be able to get faster sync speeds, based on the current SNR margins? Is this something that I have to request from talktalk, or do their connections self adjust like BT ADSL?

Upstream attenuation should be roughly half of downstream attenuation - so I imagine you have a problem with your line or the router.

Ideally with a downstream attenuation of 35dB you should be able to achieve a sync speed of 10000Kbps, or more, if the sync time SNRM can be lowered to 6dB...

Upstream sync might be expected to be 1022Kbps with a SNRM of ~9dB and an attenuation of approximately between 17dB and 20dB.

The above figures are be based on a ADSL2+ (G.992.5 annex A) interleaved residential connection and a TT business LLU connection may be different?

You're on TT's default noise margin of 12db, call them up and ask to be put on a 6db profile. This should give you ~10 meg sync speeds. They can also remove interleaving (useful if you game and/or into voip) and assign you a static ip address (free) if you need one.

Edited by deleted (Sat 20-Apr-13 13:35:53)

I've no idea why the upstream attenuation is higher than the downstream. It works perfectly fine, no drop outs or disconnects. We've just switched from a BT connection, but I can't remember what the attenuation figures were previously. It seems like there's a bit more headroom on TT LLU ADSL 2+ than there was on BT's ADSL max.

I already have a static IP (deafult for a business connection), but I will ask them to change us onto a 6db profile then. Not sure about interleaving (it is enabled and we do use voip), it isn't causing us any noticeable problems at present, just feel like it might be asking for trouble to change to a 6db profile and turn off interleaving at the same time!

In that case leave interleaving on as interleaving profiles sync half a meg or so higher than fastpath on TT.