7800n Serious sync speed problem

Grimloid
Posts: 11
Joined: Sat May 19, 2012 7:47 pm

Re: 7800n Serious sync speed problem

Post by Grimloid »

:oops: So it is, I've no idea how I missed that the first time! It's intact.
Tomken
Posts: 467
Joined: Tue Jul 26, 2011 10:31 am
Location: Co Durham

Re: 7800n Serious sync speed problem

Post by Tomken »

I didn't realise there was a seal either, just as well I hadn't as I may have peeled it off thinking it was just an inspection passed type sticker.
Grimloid
Posts: 11
Joined: Sat May 19, 2012 7:47 pm

Re: 7800n Serious sync speed problem

Post by Grimloid »

WOW!!!! I am so glad I listened to all of you.
Day before yesterday, I ordered another 7800n from DABS, it arrived today, plugged it in, and hey presto, sync was 3657K, I tweaked the snr from -1 (default) to 3, plugged it in again and now syncing at 6092k.

Was 3 a good setting to try with first, or do you think I should go higher/lower?

Thanks guys,

Grim.
billion_fan
Posts: 5398
Joined: Tue Jul 19, 2011 4:30 pm

Re: 7800n Serious sync speed problem

Post by billion_fan »

Hi Grimloid

What is the your current SNR downstream reading?

You can find this on the ADSL status page under 'Advanced >> Status >> ADSL Status'
Grimloid
Posts: 11
Joined: Sat May 19, 2012 7:47 pm

Re: 7800n Serious sync speed problem

Post by Grimloid »

Hi,
It has, since connected, disconnected twice and connected at a lower sync rate, I'm now at 4992K * opposed to the 6000 I was at earlier. I also notice that my Downstream Att, is higher than on my 2wire hgv2700.

My stats are:

Parameters
DSP Firmware Version A2pB025f.d22k
DMT Status No Defect
Operational Mode G.DMT
Upstream 448
Downstream 4992
SNR Margin(Upstream) 17.0
SNR Margin(Downstream) 10.7
Line Attenuation(Upstream) 26.5
Line Attenuation(Downstream) 55.0

These are the stats of my 2wire router. After comparing the 2 routers, the stats for the 2wire seem a lot better than the 7800n, what do you guys think, I'm considering returning it because it was quite a spend, just to get a slightly lower quality router, but if it these figures can be improved upon, that would obviously be preferred.

Modem Type: Built in modem - ADSL
DSL Line (Wire Pair): Line 1 (inner pair)
Current DSL Connection:
Down Up
Rate: 4736 kbs 448 kbs
Max Rate: 4712 kbs 856 kbs
Noise Margin: 15.0 dB 18.0 dB
Attenuation: 46.8 dB 25.5 dB
Output Power: 19.8 dBm 12.2 dBm

Protocol: G.DMT Annex A
Channel: Fast
DSLAM Vendor Information Country: {46336} Vendor: {TSTC} Specific: {0 }
ATM PVC: 0/38
ATM Circuit Identifier: VPI:0 VCI:38
ATM Encapsulation: Routed VC-Mux
ATM PVC Search: Enable
Connection Type: PPPoA

Rate Cap: 4712 kbs
Attenuation @ 300kHz: 46.8 dB
Uncanceled Echo: -19.8 dB Ok
VCXO Frequency Offset: -10.6 ppm Ok
Final Receive Gain: 26.3 dB Ok
Excessive Impulse Noise: 0 Ok

Thanks,



Grim.
billion_fan
Posts: 5398
Joined: Tue Jul 19, 2011 4:30 pm

Re: 7800n Serious sync speed problem

Post by billion_fan »

Is your SNR still tweaked?

Its does seem you 7800N is syncing a little higher then your 2wire router.

It seems the BT profile has kicked back in and dropped your sync to a more stable speed of 4992, I would stop disconnecting the ADSL for a while to let your line settle down again (if you keep disconnecting the ADSL cable the BT profile will think there is unofficial disconnections and try to drop your sync rate until it is more stable)

Some other routers line attenutaion reading are sometimes incorrect, but can't really comment on the 2wire router.
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