7800N settings for best performance

[GWReynolds]

I have recently replaced my Post Office Broadband router, ZyXEL AMG1302, with a Billion 7800N for stability and slow speed reasons. My ISP is in the process of migration to Fujitsu/TalkTalk from BT Wholesale and I have suffered very poor connection and appalling speed issues ever since September. Can someone with experience advice on how long to leave the router to settle before making any tweaks to settings for improved results? My settings are presently giving the following ADSL staus:
Parameters
DSP Firmware Version A2pB025f.d22k
DMT Status No Defect
Operational Mode G.DMT
Upstream 448
Downstream 6176
SNR Margin(Upstream) 20.0
SNR Margin(Downstream) 6.1
Line Attenuation(Upstream) 23.0
Line Attenuation(Downstream) 46.0

The Downstream value has not changed in the 2 days the router has been running though it is a little lower than the best Download rate of the ZyXEL router of 6300. This value was not stable and the router kept giving drop-outs. My best download speed is presently around 5.2 kbps Any suggestions on how to achieve the full potential of the Billion 7800N Router in my circumstance would be much appreciated.
Thank you

[Tomken]

When the migration is complete you should find yourself on ADSL2+ which should give you an increased speed to that of G.Dmt if all of the Modulation Modes are checked in the router.

When they make the change over to TalkTalk's equipment at the exchange, your router may auto reset but what I don't know is if all of the lines will be treated as new connections - the letter from the PO should explain what will happen at the change over, but if it hasn't then you should contact them for clarification.

Normally for actual new accounts with TalkTalk everyone is put on a 12dB Interleaved profile for a 10 day training period, while their DLM monitors the line and if it remains stable and you don't keep resetting the router, it will bring you hopefully down to 6dB.

After about 8 days you can reboot the router if it's still showing as 9dB or if the SNRM is looking healthy (above the profile value) and you think you should have a better speed.

I'm a TalkTalk customer and because of lower speeds than I would expect (long story), they sent me one of their newer routers (D-Link 3680) and reset the DLM.

My Downstream Atten. has since dropped from ~49 to 47. something and is now on 46.4 and I was then getting speeds of 6.6 - ~6.7 until a power cut which wasn't restored until late evening and because it didn't come back in quite as high, I switched the router off overnight until about 8.30 the next morning and for the last 3 weeks it has been sync'd at 6820.

As the 7800N tends to sync a little lower that TalkTalk's routers, I would expect my 7800N to sync at 6.5 - 6.6 but as their router is performing well, I've decided to leave that connected for the time being.

If the 5.2 speed that you are getting is your throughput, then that is comparable to the sync speed of 6176 with it being ~85% and once you are on ADSL2+ you should see an improvement, but find out if your line will be going through a training period after the migration.

[GWReynolds]

Thank You,Tomken, this is very useful and I'll look out for the likely changes to expect as migration is fully completed. My problem is that the P.O. Home Broadband do not give out any useful information to customers and their help-line staff are not sufficiently knowledgeable to answer technical questions. When this process begins, as you describe, would I be best to leave SNR tweaks alone and leave normal settings to continue as the training continues? I'll make contact with the P.O.and see what I can establish regarding the timing of this migration. Once again thank very much for your detailed and valuable comments which were most appreciated.

[tinytim]

I would definitely NOT do any tweaking for the first few weeks , let the system settle first otherwise you could mess it all up.

[babis3g]

Don't mean to cost confusion but when i was with TT till last july if their DLM is based on this
http://www.paulwills.talktalk.net/Profiles.htm
then i would say it only needs about 3 days ... personal i have gave many manual reboots, changed modems, sometimes electic cut off due to the no credits in the electric meter and always after 3rd day the dlm was going up ... i also not believe it needs weeks to do snr changes

EDIT
In the worst case ask TT to lock your profile to the desired working best ... at their forums (in the past) they did put up or down as requested